UE#12#–E5# PraqueInnovanteetVeille technologique

UE 12 – E5 Pra+que Innovante et Veille

technologique

Stéphane PERREY (PR) [email protected]

L’innovation peut se définir comme un processus qui a : -  pour intention une action de changement

et -  pour moyen l’introduction d’un élément

ou d’une méthode/approche dans un contexte déjà structuré

3

Innover, c’est

• Prendre des ini+a+ves •  S’engager et Agir •  Analyser son ac+on

4

Philosophie

•  Innover –  du verbe d’action, introduire du « nouveau »… –  à l’action elle-même, innovation dans les approches

•  Expérimenter –  du verbe d’action, tester par des expériences … –  à l’expérimentation, intervention expérimentale.

•  Clarifier : une nécessité .

Méthodes d’entraînement

•  Entraînement fonc+onnel •  Entraînement croisé •  Entraînement en hypoven+la+on, avec occlusion . . . •  Exploita)on : Profil de Puissance Record – Profil Force Vitesse

. . .

Méthodes en muscula+on

•  La méthode Cluster •  Le 4-‐7

•  L’entraînement ondulatoire •  Le Kaatsu training : réduc+on flux sanguin •  . . .

Validité écologique ? Etat de l’art : Impacts physiologiques et fonc)onnels (performance)

UE 12 – Innova+on & Entraînement

Tout ce que vous avez voulu connaître sur : _______

Vous vous intéressez aux techniques d'entrainement du futur, cet atelier est fait pour vous. Exemple de sujet traité : ____________

WORKSHOP October -‐ November – 2020

Master 2 in Strength & Condi+oning

En pra'que

2 phases

•  Présenta+on par groupe : – Introduc+on/sensibilisa+on – Ques+ons/réponses

•  Séance mise en pra+que :

– TD avec support écrit

A^endus

•  Présenta+on/introduc+on –  Les études réalisées -‐ Résultats & Analyses / moyens d’ac+ons / preuve

– Avantage, plus value, apport (s)

•  Applica+ons pra+ques * (document écrit support : déroulé, contexte..) •  En conclusion, . . .

–  recommanda+ons

Références : 5

Calendrier

•  Octobre –  Vendredi 2 : introduc+on – choix – 1ère réflexions

•  Novembre –  Mercredi 18 : ________ –  Lundi 23 : ________

Quelques réflexions (2) . . .

L’entraînement intermi^ent à haute intensité : une stratégie plus efficace pour développer

le ‘poten+el’ aérobie ?

1

Fonctions physiologiques « boostées »

Respiration a. Diffusion en O2 b. Ventilation c. Rapport VA/Q d. Affinité Hb-O2

Circulation centrale a. Débit cardiaque (FC, VES) b. Pression sanguine artérielle c. Concentration en Hb

Circulation périphérique a. Débit vers les autres tissus b. Débit sanguin musculaire c. Densité capillaire musculaire d. Diffusion en O2 e. Conductance vasculaire f. Extraction en O2 g. Affinité en O2

Métabolisme musculaire a. Potentiel enzymatique et oxydatif b. Stock énergétique c. Myoglobine d. Mitochondrie e. Masse musculaire et type de fibres f. Apport des substrats

·

8Office fédéral du sport OFSPOHaute école fédérale de sport Macolin HEFSM


Puissance aérobie

Facteurs métaboliques et cardiovasculaires

(Puissance anaérobie)Capacité anaérobie

Force, puissance, vitesse

Facteurs neuromusculaires

Entraînement de la force

Entraînement du sprint

Entraînement général de l’endurance

Résistance«all out»

Le but de l’entraînement aérobie est d’optimiser les processus

d’adaptation au niveau cardio-circulatoire et musculaire.

Comment ?

Les méthodes d’entraînement

J Physiol 586.1 (2008) pp 1–2 1

PERSPECT IVES

Specificity of trainingadaptation: time for a rethink?

John A. HawleySchool of Medical Sciences, RMIT University,Bundoora, Victoria 3083, Australia

Email: [email protected]

The key components of any trainingprogramme are the volume (how much),intensity (how hard) and frequency (howoften) of exercise sessions. These ‘trainingimpulses’ determine the magnitude ofadaptive responses that either enhance(fitness) or decrease (fatigue) exercisecapacity (Hawley, 2002). A long held viewis that the training response/adaptationis directly related to the volume ofexercise undertaken (Fitts et al. 1975).However, there is obviously a thresholdvolume/duration beyond which additionalstimuli do not induce further increases infunctional capacity. This ‘biological ceiling’is important because it implies that theregulatory control mechanisms signallingadaptive responses are ultimately titrated byexercise duration (Booth & Watson, 1985).Competitive athletes are all too aware ofthis phenomenon: many elite performerswalk a tightrope between chronic intensivetraining and inadequate recovery that canculminate in decrements in performanceand the ‘overtraining syndrome.’ Biologicalscientists are also mindful that trainingvolume and adaptation can be dissociated.Over 35 years ago Dudley et al. (1982)demonstrated that rats undertaking intenseworkbouts for shorter time induced similarincreases in the maximal activities ofseveral oxidative enzymes (i.e. cytochromec) to those observed after more prolongedsubmaximal exercise training.

One of the key tenants of exercisephysiology is the principle of trainingspecificity, which holds that trainingresponses/adaptations are tightly coupledto the mode, frequency and durationof exercise performed (Hawley, 2002).This means that the vast majority oftraining-induced adaptations occur only inthose muscle fibres that have been recruitedduring the exercise regimen, with little orno adaptive changes occurring in untrainedmusculature. Furthermore, the principleof specificity predicts that the closer the

training routine is to the requirementsof the desired outcome (i.e. a specificexercise task or performance criteria), thebetter will be the outcome. In this issueof The Journal of Physiology, the resultsof study by Burgomaster et al. (2007)force us to rethink some of our long heldbeliefs regarding the concept of trainingspecificity and response/adaptation, aswell as providing a reminder that forcertain individuals, very intense trainingcan be a time-effective and potentstimulus for inducing many of the benefitsnormally associated with more prolonged,submaximal endurance-type workouts.

In their recent investigation Burgomasteret al. (2007) report that 6 weeks oflow-volume, high-intensity sprint traininginduced similar changes in selectedwhole-body and skeletal muscle adaptationsas traditional high-volume, low-intensityendurance workouts undertaken for thesame intervention period. Specifically,they show that four to six 30 s sprintsseparated by 4–5 min of passive recoveryundertaken 3 days per week results incomparable increases in markers ofskeletal muscle carbohydrate metabolism(i.e. total protein content of pyruvatedehydrogenase), lipid oxidation (i.e.maximal activity of β-3-hydroxyacylCoA dehydrogenase) and mitochondrialbiogenesis (i.e. maximal activity ofcitrate synthase and total protein contentof the peroxisome-proliferator-activatedreceptor-γ coactivator-1α) as when subjectsundertook 40–60 min of continuoussubmaximal cycling a day for 5 days perweek. These findings are particularlyimpressive given that weekly trainingvolume was ∼90% lower in thesprint-trained group (∼225 versus2250 kJ week−1) resulting in a totalcumulative training time of ∼1.5 versus4.5 h per week. While the present studydesign did not incorporate a functionaloutcome measure of exercise capacity orperformance, this same group (Gibala et al.2006) using identical training protocols buta shorter intervention period (14 days),have previously reported no differences inthe time to complete two discrete exerciseperformance tasks: one a short-term,high-intensity test lasting ∼2 min and theother a longer trial of ∼55–60 min duration.Taken collectively, the results from thesestudies are exciting, particularly as ‘lack

of time’ is a common barrier to exerciseparticipation and adherence regardless ofsex, age or health status.

As with all studies, one should usecaution when extrapolating the resultsbeyond the specific conditions of theinvestigation. With regard to the time courseof training-induced responses, it may be thathigh-intensity sprint training stimulates amore rapid up-regulation of selected physio-logical/metabolic markers than traditionallow-intensity endurance training, but thatover a longer period, the two trainingregimens elicit similar adaptations. Timecourse studies would resolve this question.Whether or not patients with risk factorsfor metabolic disease respond as positivelyto sprint training as young, healthyindividuals also needs to be established.This is particularly relevant as continuousaerobic exercise has traditionally beenrecommended for fat loss because theproportion of lipid-based fuels oxidizedduring low-intensity exercise is greater thanduring high-intensity exercise. As obesityis strongly associated with a cluster ofchronic metabolic disorders (Hawley, 2004),any reduction in lipid oxidation or totaldaily energy expenditure would not be afavourable outcome for these individuals.Notwithstanding these concerns, the novelfindings of Burgomaster et al. (2007)provide a platform for exercise physio-logists, exercise biochemists and molecularbiologists to undertake a systematic andcomprehensive evaluation of the specificadaptations induced by different trainingstrategies in both healthy and diseasedpopulations. As previously noted (Hawley,2004) a determination of the underlyingbiological mechanisms that result from awide variety of divergent exercise trainingprotocols in association with appropriatefunctional outcome measures of exercisecapacity is crucial in order to definethe precise variations in physical activitythat produce the most desired effects ontargeted risk factors for disease and toaid in the development and subsequentimplementation of such interventions.

References

Burgomaster KA, Howarth KR, Phillips SM,Rakobowchuk M, MacDonald MJ, McGee SL& Gibala MJ (2008). J Physiol 586, 151–160.

C© 2008 The Author. Journal compilation C© 2008 The Physiological Society DOI: 10.1113/jphysiol.2007.147397

J Physiol 586.1 (2008) pp 1–2 1

PERSPECT IVES

Specificity of trainingadaptation: time for a rethink?

John A. HawleySchool of Medical Sciences, RMIT University,Bundoora, Victoria 3083, Australia

Email: [email protected]

The key components of any trainingprogramme are the volume (how much),intensity (how hard) and frequency (howoften) of exercise sessions. These ‘trainingimpulses’ determine the magnitude ofadaptive responses that either enhance(fitness) or decrease (fatigue) exercisecapacity (Hawley, 2002). A long held viewis that the training response/adaptationis directly related to the volume ofexercise undertaken (Fitts et al. 1975).However, there is obviously a thresholdvolume/duration beyond which additionalstimuli do not induce further increases infunctional capacity. This ‘biological ceiling’is important because it implies that theregulatory control mechanisms signallingadaptive responses are ultimately titrated byexercise duration (Booth & Watson, 1985).Competitive athletes are all too aware ofthis phenomenon: many elite performerswalk a tightrope between chronic intensivetraining and inadequate recovery that canculminate in decrements in performanceand the ‘overtraining syndrome.’ Biologicalscientists are also mindful that trainingvolume and adaptation can be dissociated.Over 35 years ago Dudley et al. (1982)demonstrated that rats undertaking intenseworkbouts for shorter time induced similarincreases in the maximal activities ofseveral oxidative enzymes (i.e. cytochromec) to those observed after more prolongedsubmaximal exercise training.

One of the key tenants of exercisephysiology is the principle of trainingspecificity, which holds that trainingresponses/adaptations are tightly coupledto the mode, frequency and durationof exercise performed (Hawley, 2002).This means that the vast majority oftraining-induced adaptations occur only inthose muscle fibres that have been recruitedduring the exercise regimen, with little orno adaptive changes occurring in untrainedmusculature. Furthermore, the principleof specificity predicts that the closer the

training routine is to the requirementsof the desired outcome (i.e. a specificexercise task or performance criteria), thebetter will be the outcome. In this issueof The Journal of Physiology, the resultsof study by Burgomaster et al. (2007)force us to rethink some of our long heldbeliefs regarding the concept of trainingspecificity and response/adaptation, aswell as providing a reminder that forcertain individuals, very intense trainingcan be a time-effective and potentstimulus for inducing many of the benefitsnormally associated with more prolonged,submaximal endurance-type workouts.

In their recent investigation Burgomasteret al. (2007) report that 6 weeks oflow-volume, high-intensity sprint traininginduced similar changes in selectedwhole-body and skeletal muscle adaptationsas traditional high-volume, low-intensityendurance workouts undertaken for thesame intervention period. Specifically,they show that four to six 30 s sprintsseparated by 4–5 min of passive recoveryundertaken 3 days per week results incomparable increases in markers ofskeletal muscle carbohydrate metabolism(i.e. total protein content of pyruvatedehydrogenase), lipid oxidation (i.e.maximal activity of β-3-hydroxyacylCoA dehydrogenase) and mitochondrialbiogenesis (i.e. maximal activity ofcitrate synthase and total protein contentof the peroxisome-proliferator-activatedreceptor-γ coactivator-1α) as when subjectsundertook 40–60 min of continuoussubmaximal cycling a day for 5 days perweek. These findings are particularlyimpressive given that weekly trainingvolume was ∼90% lower in thesprint-trained group (∼225 versus2250 kJ week−1) resulting in a totalcumulative training time of ∼1.5 versus4.5 h per week. While the present studydesign did not incorporate a functionaloutcome measure of exercise capacity orperformance, this same group (Gibala et al.2006) using identical training protocols buta shorter intervention period (14 days),have previously reported no differences inthe time to complete two discrete exerciseperformance tasks: one a short-term,high-intensity test lasting ∼2 min and theother a longer trial of ∼55–60 min duration.Taken collectively, the results from thesestudies are exciting, particularly as ‘lack

of time’ is a common barrier to exerciseparticipation and adherence regardless ofsex, age or health status.

As with all studies, one should usecaution when extrapolating the resultsbeyond the specific conditions of theinvestigation. With regard to the time courseof training-induced responses, it may be thathigh-intensity sprint training stimulates amore rapid up-regulation of selected physio-logical/metabolic markers than traditionallow-intensity endurance training, but thatover a longer period, the two trainingregimens elicit similar adaptations. Timecourse studies would resolve this question.Whether or not patients with risk factorsfor metabolic disease respond as positivelyto sprint training as young, healthyindividuals also needs to be established.This is particularly relevant as continuousaerobic exercise has traditionally beenrecommended for fat loss because theproportion of lipid-based fuels oxidizedduring low-intensity exercise is greater thanduring high-intensity exercise. As obesityis strongly associated with a cluster ofchronic metabolic disorders (Hawley, 2004),any reduction in lipid oxidation or totaldaily energy expenditure would not be afavourable outcome for these individuals.Notwithstanding these concerns, the novelfindings of Burgomaster et al. (2007)provide a platform for exercise physio-logists, exercise biochemists and molecularbiologists to undertake a systematic andcomprehensive evaluation of the specificadaptations induced by different trainingstrategies in both healthy and diseasedpopulations. As previously noted (Hawley,2004) a determination of the underlyingbiological mechanisms that result from awide variety of divergent exercise trainingprotocols in association with appropriatefunctional outcome measures of exercisecapacity is crucial in order to definethe precise variations in physical activitythat produce the most desired effects ontargeted risk factors for disease and toaid in the development and subsequentimplementation of such interventions.

References

Burgomaster KA, Howarth KR, Phillips SM,Rakobowchuk M, MacDonald MJ, McGee SL& Gibala MJ (2008). J Physiol 586, 151–160.

C© 2008 The Author. Journal compilation C© 2008 The Physiological Society DOI: 10.1113/jphysiol.2007.147397



Puissance aérobie


Puissance anaérobieCapacité anaérobie



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Juho Pietari «Hannes» Kolehmainen 1889-1966 (FIN):

• 3 médailles d’or aux JO de 1912: 5000 m (14:36,6 (WR)),

10 000 m, 12 000 m cross

• 5-10 intervalles de 1000 m (19 km/h – 3:05 min)

Paavo Nurmi 1897-1973 (FIN):

• 9 médailles d’or aux JO en course de fond: 5000 m en 14:36 min

• Entraînement par intervalles courts, p. ex. 6 x 400 m en 60 s

(24 km/h) lors d’une course en forêt de 10 à 20 km

1959 Dr Herbert Reindell (1908-1990, cardiologue) et Helmut

Roskamm

• Entraînement par intervalles chez des patients cardiaques en

réadaptation

• Première description de l’entraînement par intervalles dans une revue scientifique (Schw. Z. Sportmed., 1959; 7: 1-8)

Hannes Kolehmainen

Paavo Nurmi, en 1920

3

L’entraînement à Haute Intensité (HIT) : découverte récente ou réalité ancienne ?

Stöggl (2016)

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l’entraînement par intervalles est une méthode répandue chez les coureurs européens:

Emil Zatopek (CZE: 3 médailles aux JO de 1952)

Gordon Pirie (GBR, en 1960: 3000 m en 7:57) (5 records du monde entre 1952 et 1956)

Siegfried Hermann (GER, 800 m en 1:48 et 1500 m en 3:40,9) entraîné par Toni Nett

Roger Moens (BEL)

Vladimir Kutz (URSS, 5000 m en 13:35,0 en 1955/1956)

Siegfried Hermann

Gordon Pirie

5

Stöggl (2016)

L’entraînement à Haute Intensité (HIT) : les années 1950

Stöggl (2016)


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10 000 m record du monde 1954: 28:54,2Record d’Autriche: 27:36 par Weidlinger Günter en 2008

Emil Zatopek (1922-2000)

JO de Londres de 1948Or sur 10 000 mArgent sur 5000 m

JO d’Helsinki de 1952Or sur 5000 mOr sur 10 000 mOr au marathon

«Entraîne-toi très dur; ainsi, la compétition te paraîtra plus facile.»(Emil Zatopek)

«Il m’est arrivé de voir Zatopek courir 60 fois 400 m lors d’un entraînement. [...]Mais, l’année des JO de 1948, alors qu’il se préparait pour le 10 000 m, il acouru 60 fois 400 m pendant dix jours.» (Toni Nett, 1956)

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Années 1950: Roger Bannister (entraîné par Franz Stamfl) (premier à courir le mile en moins de 4 min) Différents entraînements par intervalles (aérobie,

anaérobie)

Intervalles 5 jours par semaine presque tout au long de l’année

Qualitatif plutôt que quantitatif

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Vladimir Kutz (1927-1975):•Or décroché haut la main aux JO de

1956 sur 5000 et 10 000 m•Record du monde sur 5000 et 10 000 m

(en 1956/1957)(Billat, Sports Med., 2001)

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Ernst van Aaken (1919-1984):

Principales caractéristiques:• Courir de longues distances au quotidien (10-80 km)• Adopter une vitesse modérée (130 bpm)• Eviter le déficit en O2 et la production d’acide lactique• Parvenir à un rapport entraînement purement aérobie vs

efforts anaérobies de 40:1• Observer des pauses fréquentes jusqu’à récupération

complète

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La méthode d’endurance pure

Stöggl (2016)

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A partir d’un certain volume d’entraînement, la hausse de ce dernier n’entraîne plus d’amélioration des performances en compétition.

Nécessité d’améliorer la qualité de l’entraînement (intensité, force, vitesse, technique)

Costill et al. (1988, 1991): doublement du volume d’entraînement (de 4266 à8670 m/jour) pas de modification de la capacité aérobie ni anaérobie

Pyne et al. (2001): Nageurs de classe mondiale: •Amélioration des résultats aux tests (t200m), de la tolérance à l’acide lactique (v5mmol et v10mmol) et du seuil anaérobie•Pas d’amélioration des performances en compétition

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L’entraînement en Volume

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s Années 1960: premières études scientifiques sur l’entraînement par intervallesPer-Olof Åstrand (SWE) développe l’entraînement par intervalles longs à une allure comprise entre la «vitesse critique» et la vVO2max (90-95% du VO2max).Åstrand et al. (1960) considèrent cette méthode comme la meilleure pour accroître le VO2max, tous les paramètres cardio-respiratoires étant au maximum.Christensen et al. (1960) mènent les premières études sur l’entraînement intermittent par intervalles(intervalles de 5 à 30 s) en lien avec le VO2max et la formation d’acide lactique.

• 10 s à 100% de la vVO2max avec 10 s de pauseIntervalles de 15 s/15 s à 100% de la vVO2max pendant 30 min avec seulement 2,3 mmol/l d’acide lactique + VO2max atteint à la fin

• Intervalles de 15 s/10 s 95% du VO2max atteint à la 18e min avec 5,6 mmol/l d’acide lactique

• Intervalles de 5 s/5 s seulement 81% du VO2max avec 2,5 mmol/l d’acide lactique

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L’entraînement à Haute Intensité (HIT) : Les premières preuves.. Les années 1960

Stöggl (2016)

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Années 1970: VO2max mesuré systématiquement chez les athlètes

Années 1980: seuil d’acide lactique introduit en tant que paramètre de mesure (p. ex. Alois Mader: seuil de 4 mmol/l)

Sebastian Coe (GBR): 1979-84: 2 médailles d’or aux JO, 4 records du monde (800 m, 1000 m, 1500 m, mile)

• Entraînement aérobie et anaérobie par intervalles Saïd Aouita (MAR) domine dans les années 1980 sur les

distances comprises entre 800 et 5000 m.• Entraînement intensif par intervalles à différentes vitesses

L’intensité de l’entraînement par intervalles a été déterminée sur la base des vitesses relevées en compétition sur 800 à 5000 m, sans tenir compte des marqueurs physiologiques.

Sebastian Coe

Saïd Aouita

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L’entraînement à Haute Intensité (HIT) : les années 1970-80

« All of them have trained wrong .. »

Wisløff

Distance training has minimal effect •"What use do you have from distance training other than recovery? •Probably nothing. It may be a nice thing to do if you have time and enjoy being outside, but it gives minimal or no training effect. •Instead of distance training you should rather ’hang out’ with friends – it gives you the same cardiovascular training benefits

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s Le HIT comme méthode efficace pour accroître le VO2max dans les cas suivants:

• Sports collectifs et de combat d’endurance (Sperlich, 2010a, b; Stöggl et al., 2010; Laursen et al., 2002; Franch et al., 1998; Rodas et al., 2000; Harmer et al., 2000; Tabata et al.,1996; Helgerud et al., 2001; Esfarjani & Laursen, 2007; Perry et al., 2008; etc.)

• Patients coronariens (p. ex. Wisløff et al., 2007; Rogmo et al., 2004)• Patients victimes d’un syndrome métabolique (p. ex. Thonna et al., 2008 et

2009)• Patients atteints de broncho-pneumopathie chronique obstructive (BPCO) (p. ex.

Glöckl, 2008)

Plus forte amélioration du VO2max avec un HIT qu’avec un entraînement modéré sur une durée identique (p. ex. Helgerud et al., 2007)

Adaptations similaires avec un HIT et des efforts submaximaux ou de faible intensité de durée identique(p. ex. Gibala et al., 2009; Burgomaster et al., 2008)

Amélioration de l’endurance aérobie et anaérobie par le HIT (Gibala et al. 2006; Ratel et al., 2004).

HIT plus motivant et varié que l’entraînement continu (Bartlett et al., 2011; Lambrick et al., 2015)

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L’entraînement à Haute Intensité (HIT) : De nos jours

L’entraînement à Haute Intensité (HIT) est ‘Aérobie et Anérobie’

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(Åstrand et al., 2003)

Spencer et al. (1996): le système aérobie joue déjà un rôle déterminant sur une course de 400 m.•VO2max atteint dans les 20 dernières secondes•46% de l’énergie totale via la phosphorylation oxydative•800 m et 1500 m 69% et 83% aérobie

Définition de Billat (2011): intervalle aérobie: lorsque le pourcentage du métabolisme aérobie est plus élevé que celui du métabolisme anaérobie.

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L’entraînement à Haute Intensité (HIT) est ‘Aérobie et Anérobie’

L’entraînement à Haute Intensité (HIT) : Formes aérobies

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s Durée de l’intervalle: 15 s 30 s 45 s 1 min 2 min 3 min 4 min 5 min 6 min 7 min 8 min

9 min 10 min...16 min

Entraînement intermittent par intervalles

Méthode d’entraînement optimale pour améliorer le VO2max•Sollicitation maximale et la plus longue possible du système cardio-vasculaire

•Haute intensité (qualité technique) sur une longue durée

•Intensité: 90-95% de la FCmax

•Domaine situé entre la «vitesse critique» et la vVO2max (100-105%) (Midgley, 2006)

•Accroissement maximal de la période passée au VO2max

•Observation de pauses pour réduire la sensation de fatigue musculaire

0

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Intermittent

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90 -95 % HF max

4 x 4 min à 90-95% de la FCmax

(3 min de pause active à 70%)

Entraînement aérobie classique par intervalles

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L’entraînement à Haute Intensité (HIT) : Formes aérobies

Stöggl (2016)

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s Entraînement intermittent:Effort prolongé se caractérisant par une alternance constante entre de brèves phases à haute intensité (qualité maximale) et d’autres à faible intensité.

(Hegner, Schütz et Vogt, 2007)

Exemples de protocole intermittent:•30 s/30 s (10-30 x)•15 s/15 s (20-60 x)•1 min/1 min (10-15 x)•Intensité: 90-105% de la vVO2max (90-95% de la FCmax), récupération à 50% de la vVO2max (70% de la FCmax)•1-3 séries/unité•1-2 x/semaine•Bon échauffement(d’après Midgley & McNaughton, 2006; Helgerud et al., 2007; Stöggl, 2010 ss)

HIT 30 x 30 s/30 s

HIT 15 x 1 min/1 min

29

L’entraînement à Haute Intensité (HIT) : Formes anaérobies

thom

as.s

toeg

gl@

sbg.

ac.a

t–Le

HIT

au

fil d

u te

mp

s Entraînement par intervalles en sprint (Sprint Interval Training – SIT) ou «Burst Training»:Consiste en des intervalles d’une durée inférieure à 1 min et d’une intensité comprise entre plus de 100% de la vVO2max et le niveau maximal qu’elle puisse atteindre.Malgré l’intensité maximale de l’effort (répété), les systèmes aérobie et cardio-vasculaire sont sollicités au maximum pour fournir l’énergie nécessaire. (voir ouvrage de Mark J. Smith, 2008)

33

L’entraînement à Haute Intensité (HIT) : Formes anaérobies

thom

as.s

toeg

gl@

sbg.

ac.a

t–Le

HIT

au

fil d

u te

mp

s Intervalles de Tabata (Tabata et al., 1996, MSSE)

Nommée d’après Izumi TabataConcept mis en pratique par des sportifs d’élite japonaisDonnées de l’entraînement

• 7-8 x 20 s à 170% de la vVO2max avec 10 s de pause entre les intervalles (cyclo-ergomètre)

• Durée totale sans échauffement ni étirements: 4 min• 5 jours/semaine pendant 6 semaines

Résultats• du VO2max de 7 ml/min/kg• de la capacité anaérobie de 28%

(déficit en O2 maximal cumulé)

Izumi Tabata

34

Temps Vitesse tapis

VO2max

Fin exercice (3 min)

VO

2

VO

2

déficit initial

déficit lié à l’exercice supra-maximal

110 %"

Déficit Accumulé en Oxygène (AOD)

AOD : mesure indirecte de la capacité Anaérobie MAOD: AOD maximal



Puissance aérobie


Puissance anaérobieCapacité anaérobie



10/20

15/15

30/30

5/25

5/15

Formes de jeu adaptées15/90

15/45

Intensité (quasi) maximale

Quelques méthodes . . .


Aerobe LeistungAnaerobe LeistungAnaerobe Kapazität

Kraft, Leistung, Schnelligkeit

Quel système est fortement sollicité?



HIT

1) Puissance externe: • Distance parcourue • Niveau de l’accélération• Nombre d’accélérations

2) Effort cardiovasculaire: • Fréquence cardiaque• Temps (sec) dans différentes zones

d’intensité

3) Effort métabolique: • Concentration de lactate

4) Effort: • Perception subjective de l’effort• Echelle de Borg 1-20

LPM

FréquencecardiaqueLactate

Sollicita+on des systèmes

Le concept de base L'entraînement fractionné ou par intervalles ou intermittent ou par répétitions Alternance de plusieurs cycles comprenant :

•  une phase de travail (intensité importante) suivie •  d'une phase de récupération passive (repos) ou

active (intensité faible).

predict, since the factors are inter-related. While our

understanding of how to manipulate these variables is

progressing with respect to T@ _VO2max [14], it remains

unclear which combination of work-interval duration and

intensity, if any, is most effective at allowing an individual

to spend prolonged T@ _VO2max while ‘controlling’ for thelevel of anaerobic engagement [3] and/or neuromuscular

load (review Part II).Considering that long-term physiological and perfor-

mance adaptations to HIT are highly variable and likely

population-dependent (age, gender, training status andbackground) [19, 20], providing general recommendations

for the more efficient HIT format is difficult. We provide,

however, in Part I of this review, the different aspects ofHIT programming, from work/relief interval manipulation

to the selection of exercise modality, with continued ref-

erence to T@ _VO2max (i.e. time spent C90 % _VO2max,otherwise stated), which may assist to individualize HIT

prescription for different types of athletes. Additional

programming considerations will also be discussed withrespect to other variables, such as cardiovascular responses.

Different examples of training cycles from different sports

will be provided in Part II of the present review. As thiswas a narrative, and not a systematic review, our methods

included a selection of the papers we believed to be most

relevant in the area. Since the main goal of HIT sessions is

to improve the determinants of _VO2max, only HIT sessions

performed in the severe intensity domain (i.e. greater than

the second ventilatory threshold or maximal lactate steadystate) were considered. Acute responses to running-based

HIT were given priority focus, since the largest quantity of

literature has used this exercise mode. It is likely, however,that the manipulation of these same HIT variables has

comparable effects in other sports (or exercise modes, e.g.

cycling, rowing, etc.), with the exception of under-wateractivities that may require a specific programming

approach [36]. Finally, we believe that the present rec-

ommendations are essentially appropriate for moderatelytrained to elite athletes. For special populations (e.g. sed-

entary or cardiac patients), the reader is referred to recent

reviews [37] and original investigations [38–40]. Stan-dardized differences (or effect sizes; ES [41]) have been

calculated where possible to examine the respective effects

of the manipulation of each HIT variable, and interpretedusing Hopkins’ categorization criteria, where 0.2, 0.6, 1.2

and[2 are considered ‘small’, ‘medium’, ‘large’ and ‘very

large’ effects, respectively [42].

2 Prescribing Interval Training for Athletesin the Field

To prescribe HIT and ensure that athletes reach therequired intensity, several approaches exist to control and

individualize exercise speed/power accordingly. We will

discuss these points and illustrate why, in our opinion,using incremental test parameters is far more objective,

practical, and likely more accurate and effective at

achieving desired performance outcomes.

2.1 The Track-and-Field Approach

To programme HIT for endurance runners, coaches have

traditionally used specific running speeds based on set

times for distances ranging from 800 m to 5000 m, butwithout using physiological markers such as the speeds

Work

Relief

Duration

Duration

Inte

nsity

Inte

nsity

Series

Series duration

Time between series

# of series

Work modality

Between-seriesrecovery intensity

Fig. 2 Schematic illustration ofthe nine variables defining aHIT session adapted fromBuchheit [35]. HIT high-intensity interval training

M. Buchheit, P. B. Laursen

Author's personal copy

Buchheit, Laursen (2014)

9 variables


Paramètres de contrôle

Intensité

Temps

1

Intensité de l’effort

2Durée de l’effort

3

Durée des pauses

Intensité des pauses

4

Nombre de répétitions6

8

Nombre de séries7

Durée des pauses entre les séries

Type d’effort5

9

Intensité des pauses entre les séries

Paramètres de contrôle

Terminologie -‐ standardisa+on

•  « high intensity interval training » HITT : s+mulus proche du maximum ou intensité cible 80-‐100% de la FCmax. •  « sprint interval training » SIT : exercice à intensité supramaximale (all-‐out) avec intensité cible > à 100% VO2max. •  « moderate-‐intensity con+nuous training » MICT

Weston et al. (2014)

En résumé,

aspects of program design, with a particular focus on the

application of interval training for athletic performance[19, 20].

2 Characterizing the Training Stimulus: StandardizingTerminology

Interval training refers to the basic concept of alternating

periods of relatively intense exercise with periods of lower-intensity effort or complete rest for recovery. A wide range

of terms have been used by different groups to describe

various interval training protocols, which has led to adizzying array of acronyms and general lack of standardi-

zation in the literature. Weston et al. [8] recently proposed

a simple classification scheme for interval training basedon exercise intensity as part of an effort to standardize

terminology in future studies. The authors suggested that

the term ‘high intensity interval training’ (HIIT) be used todescribe protocols in which the training stimulus is ‘near

maximal’ or the target intensity is between 80 and 100 %

of maximal heart rate (HRmax). In contrast, the authorsadvocated use of the term ‘sprint interval training’ (SIT)

for protocols that involve ‘all out’ or ‘supramaximal’

efforts, in which target intensities correspond to workloadsgreater than what is required to elicit 100 % of maximal

oxygen uptake (VO2max). Weston et al. [8] also suggested

that the standardized term ‘moderate-intensity continuoustraining’ be used where appropriate in comparative studies.

Other authors [21] have also recently considered various

methodological approaches for the classification of intervaltraining, including the use of turn-point or threshold

models to prescribe intensity rather than percentages of

HRmax or VO2max.We applaud the efforts to try and standardize interval

training terminology research in future studies. While

cognizant of the potential value in other approaches [21,22], especially for training prescription for athletes, we will

employ the basic classification scheme proposed by Wes-

ton et al. [8] in the present review, given the widespreaduse of percentages of HRmax and VO2max to describe rela-

tive exercise intensity. Weston et al. [8] used the specific

descriptors ‘peak heart rate’ and ‘maximal oxygen uptake’;in the present review we will use ‘HRmax’ and ‘VO2max’ to

describe relative intensities scaled to ‘peak’ and/or ‘max-

imal’ heart rate and oxygen uptake, respectively, for sim-plicity and consistency, and regardless of the specific term

used in original studies that are cited here. There is no

universal definition of what constitutes ‘low volume’interval training, but in the present review we will consider

protocols in which the total amount of intense exercise

performed during a training session was B10 min within atraining session, i.e. the summed total duration of the hard

efforts, excluding the recovery periods and any warm-up or

cool-down. Based on this depiction and the classificationscheme proposed by Weston et al. [8], an example of a

low-volume HIIT protocol is ten 60-s cycling efforts at an

intensity that elicits *85–90 % HRmax, interspersed by60 s of recovery [23]. An example of low-volume SIT is

the repeated Wingate Test model, which typically consists

of four to six 30-s all-out efforts at mean power outputscorresponding to *250 % of the absolute workload elic-

ited at the end of an incremental VO2max, interspersed witha few minutes of recovery [24]. An overview of common

protocols employed in interval training studies is depicted

in Fig. 1.

3 Physiological Adaptations to Low-Volume IntervalTraining

It has been recognized for some time that relatively short-term SIT and HIIT protocols can rapidly enhance the

capacity for aerobic energy metabolism [25, 26] and elicit

physiological remodeling that resembles changes inducedby MICT. While relatively few direct comparisons have

VO2 peak

Time (min)

Pow

er o

utpu

t (%

)250

200

150

100

50

00 10 20 30 40 50

Fig. 1 Examples of protocols employed in interval training studies,expressed relative to PPO that is required to elicit VO2max or VO2peak.The figure shows typical MICT, e.g. 50 min at *35 % of PPO, whichelicits *70 % of HRmax (hatched box); low-volume HIIT, e.g.10 9 1 min at a constant workload corresponding to *75 % of PPO,interspersed with 1 min of recovery, which elicits *85–90 % ofHRmax during the intervals (grey bars); and low-volume SIT, e.g.4 9 30 s ‘all out’ effort at a variable power output corresponding to*175 % of PPO (averaged over the course of the intervals),interspersed with 4 min of recovery, which elicits *90–95 % ofHRmax during the intervals (black bars). Power output and heart rateestimates are derived from Little et al. [31] and Skelly et al. [60].PPO, peak power output, VO2max, maximal oxygen uptake,VO2peak, peak VO2, MICT, moderate-intensity continuous exercise,HRmax, maximum heart rate, HIIT, high-intensity interval training,SIT, sprint-interval training

S128 M. J. Gibala et al.

123

SIT

HITT

MCIT

Weston et al. (2014)

Entraînement par intervalle « faible volume »

Séance d’entraînement : ~20-25 min (avec échauffement et retour au calme)

Durée totale exercice ‘sévère’ ≤10 min Exemples de séance : Protocole HIIT : exercice de pédalage 10 x 60 s (≈ 85-90% FCmax) avec des récupérations de 60 s

Protocole SIT : 4-6 x Wingate de 30 s (all-out, >150%) avec ~4 min de récupération.

Gibala et al. (2014)

Adapta+ons musculaires

Comparaison protocoles SIT, HIIT 1.  Amélioration à court terme du métabolisme énergétique

aérobie (Tabata et al., 1996) ? 2.  Réponses physiologiques similaires à protocole MICT ?


6 séances de SIT vs. MICT (16 sujets actifs) 21 ± 1 ans, VO2pic = 4,0 ± 0,21 l/min Biopsie vastus lateralis

Comparaison SIT vs. MICT


J Physiol 575.3 Rapid adaptations to sprint or endurance training in humans 903

Table 2. Training protocols

Parameter SIT group ET group

Work intensity ‘All out’ supramaximal 65% VO2peak

(∼700 w) (∼175 w)Exercise protocol 30 s × 4–6 repeats, 90–120 min of

(per session) 4 min recovery continuous exercise

Total exercise/training time 2–3 min (intervals only) 90–120 mincommitment per session 18–27 min (incl. recovery)

Total exercise/training time 15 min (intervals only) 630 mincommitment over 2 weeks 135 min (incl. recovery)

Total exercise volume1 ∼630 kJ (intervals only) ∼6500 kJover 2 weeks ∼950 kJ (incl. recovery)2

SIT, sprint interval training; ET, endurance training; VO2peak, peak oxygen uptake.1Based on average workloads sustained during training and 2assuming subjectscycled at the highest workload permitted during recovery (30 W) for the maximumduration (4 min) after every interval performed during training (total of 30 intervalsover 2 weeks).

‘distance covered’ on a computer monitor (i.e. 50 kJ wasequated to 2 km, and 750 kJ was equated to 30 km, suchthat visual feedback at any point during the time trial waspresented in units of distance rather than work completed).Exercise duration and average power were recorded uponcompletion of each test.

Wingate test. Subjects in the SIT group completed a 30 smaximal effort on an electronically braked cycle ergometer(Lode) at a resistance equivalent to 7.5% of their bodymass. The ergometer was interfaced with a computerloaded with software (Wingate Software Version 1.11, LodeBV) that applied the appropriate load for each subject.Subjects were instructed to begin pedalling as fast aspossible ∼2 s before the computer applied the load andreceived extensive verbal encouragement throughout thetest. Peak power, mean power and fatigue index werecalculated and recorded by an online data acquisitionsystem.

Experimental protocol

The experimental protocol consisted of (i) baseline testing(i.e. following familiarization); (ii) a 2 week trainingintervention, and (iii) post-training procedures.

Baseline testing. Prior to training, all subjects underwenta resting needle muscle biopsy procedure. The lateralportion of one thigh was anaesthetized (1% xylocaine)and a small incision made through the skin and underlyingfascia in order to obtain a tissue sample from the vastuslateralis muscle. The muscle sample was immediatelyfrozen in liquid nitrogen after removal from the leg.Subjects also performed two baseline performance testsand the timing of the tests was standardized for allsubjects. Subjects performed a 50 kJ cycling time trial 1 h

after the biopsy procedure, followed 48 h later by a 750 kJcycling time trial.

Training. The training protocol commenced ∼48 h afterthe 750 kJ time trial and consisted of six sessions spreadover 14 days, with 1–2 days recovery between trainingsessions (Table 2). Both groups performed training onMondays, Wednesdays and Fridays for 2 weeks. For the SITgroup, training consisted of repeated 30 s maximal cyclingefforts, interspersed with 4 min of recovery (rest or lightcycling at 30 W). Training progression was implementedby increasing the number of repeats from four repetitionsduring sessions 1 and 2, to five repetitions during sessions3 and 4, and finally to six repetitions during sessions 5and 6. For the ET group, training consisted of 90–120 minof continuous cycling at an intensity corresponding to65% of VO2peak. Training progression in the ET groupwas implemented by increasing the duration of exercisefrom 90 min during sessions 1 and 2, to 105 min duringsessions 3 and 4, and finally to 120 min during sessions 5and 6. All training sessions for both groups were directlysupervised by one of the study investigators.

Post-training procedures. The nature and timing of thepost-training tests was identical in all respects to thepre-training procedures. A resting needle muscle biopsysample was obtained ∼72 h after the final training session,using the same leg as for the pre-training sample butseparated by a minimum of 5 cm from the first incision.A 50 kJ time trial was performed 1 h after the biopsyprocedure, followed 48 h later by the 750 kJ time trial.

Physical activity and nutritional controls

Subjects were instructed to continue their normal dietaryand physical activity practices throughout the experiment.

C© 2006 The Authors. Journal compilation C© 2006 The Physiological Society

) by guest on December 19, 2014jp.physoc.orgDownloaded from J Physiol (

10,5 h 2,5 h

90%-

Adapta+ons ini+ales

Performance



(95◦C for 15 s, 60◦C for 60 s) and the beta2-microglobulin(β2M) signal was used as a housekeeping gene to normalizethreshold cycle (CT) values. All samples were run induplicate simultaneously with RNA- and RT-negativecontrols. In addition, the melting point dissociation curvegenerated by the instrument was also used to confirm thespecificity of the amplified product.

Muscle buffering capacity. The in vitro method of Marlin& Harris (1991) was employed, except that NaF as opposedto iodoacetic acid was used to inhibit glycolysis becauseit is acid–base neutral and would not affect the initialpH measurement (Mannion et al. 1993). Briefly, ∼3 mgof freeze-dried muscle was homogenized to a dilution of5.0 mg ml−1 in a solution of 145 mm KCl, 10 mm NaCland 5 mm NaF. After homogenization, the muscle samplewas incubated for 5 min in a hot water bath at 37◦Cand an initial pH measurement was obtained using amicroelectrode (MI-415, Microelectrodes, Inc., Bedford,NH, USA) connected to a pH meter (Denver Instruments,Denver, CO, USA). If the initial pH was below 7.10, itwas adjusted to 7.10 with 10 mm NaOH (Marlin & Harris,1991; Mannion et al. 1993). The sample was then titratedacross a physiological pH range from 7.10 to 6.50 by theaddition of 2.5 µl aliquots of 10 mm HCl. Muscle bufferingcapacity was subsequently calculated in µmol H+ (g drymuscle)−1 pH unit−1.

Muscle glycogen. Briefly, ∼2 mg of freeze-dried musclewas incubated in 2.0 n HCl and heated for 2 h at 100◦C tohydrolyse the glycogen to glucosyl units. The solution wassubsequently neutralized with an equal volume of 2.0 nNaOH and analysed for glucose using an enzymatic assayadapted for fluorometry (Passoneau & Lowry, 1993).

Statistical analyses

All data were analysed using a 2-factor analysis of variance,with one between factor (group; SIT versus ET) and onewithin factor (time; pre-training versus post-training).Analyses of mRNA data were performed by comparing thedifference between the target and reference CT values (deltaCT) as previously described (Livak & Schmittgen, 2001;Mahoney et al. 2004). The differences in the CT valuesare expressed numerically using the equation mRNA =2−deltaCT . The level of significance for all analyses was set atP = 0.05. All data are presented as means ± s.e.m. basedon n = 8 subjects per group, except for glycogen wheren = 7 for the SIT group only.

Results

Exercise performance

The time required to complete the 750 kJ cycling testdecreased after training by 10.1% and 7.5% in the SIT

and ET groups, respectively, with no difference betweengroups (main effect for time, P < 0.001) (Fig. 1). Followingtraining, there was a corresponding increase in meanpower output during the 750 kJ time trial from 212 ± 17to 234 ± 16 W in the SIT group and from 199 ± 13to 212 ± 12 W in the ET group (main effect for time,P < 0.001). Although the magnitude of improvement wassmaller, the time required to complete the 50 kJ test alsodecreased after training by 4.1% in the SIT group (Post:113 ± 6 versus Pre: 117 ± 6 s) and 3.5% in the ET group(Post: 122 ± 10 versus Pre: 115 ± 9 s) (main effect for time,P = 0.02). Following training, mean power output duringthe 50 kJ time trial increased from 435 ± 23 to 453 ± 25 Win the SIT group and 416 ± 39 to 433 ± 40 W in the ETgroup (main effect for time, P = 0.02).

Muscle oxidative capacity

The maximal activity of COX increased after training(main effect for time, P = 0.04), but there was nodifference between groups (Fig. 2). Similarly, there weretraining-induced increases in COX II and COX IV proteincontents (main effects for time, P = 0.03 and 0.04,respectively), but no difference between groups (Fig. 3).COX II and COX IV mRNAs were unchanged (P > 0.05)after training in both groups (Table 4).

Muscle buffering capacity

Muscle buffering capacity increased after training by 7.6and 4.2% for the SIT and ET groups, respectively, with nodifference between groups (main effect for time, P = 0.03)(Fig. 4).

Muscle glycogen content

Resting muscle glycogen content increased after trainingby 28 and 17% for the SIT and ET groups, respectively,with no difference between groups (main effect for time,P = 0.006) (Fig. 5).

0

PRE

SIT ET

40

50

60

70

80POST *

Figure 1. 750 kJ cycling time trial performance before (PRE) andafter (POST) 6 sessions of sprint interval training (SIT) orendurance training (ET) over 2 weeks∗P ≤ 0.05 versus pre-training (main effect for time). Lines denoteindividual data for 8 subjects in each group.



- 10,1 % - 7,5 %

Puissance (W) : 212 ± 17 à 234 ± 16 (SIT) vs. 199 ± 13 to 212 ± 12 (ET)

* P < 0,05

Capacités oxyda+ves ≈


906 M. J. Gibala and others J Physiol 575.3

Discussion

The major novel finding from the present study wasthat six sessions of either low volume SIT or traditionalhigh volume ET induced similar improvements in muscleoxidative capacity, muscle buffering capacity and exerciseperformance. To our knowledge this is the first study todirectly compare interval versus continuous training usinga research design that matched groups with respect toexercise mode (cycling), training frequency (3 × per week)and training duration (2 weeks), but differed in termsof total training volume and time commitment. Severalprevious studies have examined muscle metabolic and/orperformance adaptations to interval versus continuoustraining (Henriksson & Reitman, 1976; Saltin et al. 1976;Eddy et al. 1977; Fournier et al. 1982; Gorostiaga et al.1991; Edge et al. 2006), but the data are equivocal and in allcases the total volume of work was similar between groups.The present study was unique because, by design, the totaltraining volume for the SIT group was only ∼10% thatof the ET group (i.e. 630 versus 6500 kJ). In addition, thetotal training time commitment over 2 weeks was ∼2.5 hfor the SIT group (including the work intervals and therecovery periods between intervals), whereas the ET groupperformed continuous exercise each training day for a totalof ∼10.5 h. Thus, while previously speculated by others(Coyle, 2005), to our knowledge this is the first studyto demonstrate that SIT is indeed a very ‘time efficient’training strategy.

Effect of short-term sprint or endurance trainingon exercise performance

We are aware of only one previous study thatexamined changes in volitional exercise performance aftercontinuous or interval training. Eddy et al. (1977) hadsubjects perform cycle exercise training, 4 days per weekfor 7 weeks, using either a continuous (70% of VO2peak)or interval method (repeated 1 min bouts at 100% VO2peak

0

2

4

6

8

10PREPOST *

SIT ET

Figure 2. Maximal activity of COX measured in resting musclebiopsy samples obtained before (PRE) and after (POST)6 sessions of sprint interval training (SIT) or endurance training(ET) over 2 weeks∗P ≤ 0.05 versus pre-training (main effect for time). Lines denoteindividual data for 8 subjects in each group.

followed by 1 min of rest). The daily workload was matchedbetween groups and increased progressively from ∼100 kJper session during week 1 to ∼275 kJ per session duringweek 7. After training, subjects in both groups showedsimilar improvements during a matched-work exercisetest, such that cycling time to exhaustion at 90% of VO2peak

increased by an almost identical amount (∼26 min) inboth the continuous and interval groups. In the presentstudy, subjects performed 50 and 750 kJ cycling timetrials, which demanded work intensities equivalent to∼120 and ∼65% of peak power output elicited duringthe VO2peak tests. Consistent with the work of Eddyet al. (1977), subjects in the interval and continuoustraining groups showed remarkably similar improvementsin exercise performance. However, whereas Eddy et al.(1977) employed matched-work training protocols, the

S3 (SIT) S11 (ET)

Pre Post Pre Post

COX II

COX IV

0

1000

2000

3000

4000PREPOST *

SIT END

0

2000

4000

6000

8000

10000

12000PREPOST *

SIT END

Figure 3. Protein content of COX subunit II (middle panel) andIV (bottom panel) measured in resting muscle biopsy samplesobtained before (PRE) and after (POST) 6 sessions of sprintinterval training (SIT) or endurance training (ET) over 2 weeks∗P ≤ 0.05 versus pre-training (main effect for time). A representativeWestern blot (top panel) based on one subject from each group is alsopresented for each subunit. Lines denote individual data for 8 subjectsin each group.



* P = 0,04

906 M. J. Gibala and others J Physiol 575.3

Discussion

The major novel finding from the present study wasthat six sessions of either low volume SIT or traditionalhigh volume ET induced similar improvements in muscleoxidative capacity, muscle buffering capacity and exerciseperformance. To our knowledge this is the first study todirectly compare interval versus continuous training usinga research design that matched groups with respect toexercise mode (cycling), training frequency (3 × per week)and training duration (2 weeks), but differed in termsof total training volume and time commitment. Severalprevious studies have examined muscle metabolic and/orperformance adaptations to interval versus continuoustraining (Henriksson & Reitman, 1976; Saltin et al. 1976;Eddy et al. 1977; Fournier et al. 1982; Gorostiaga et al.1991; Edge et al. 2006), but the data are equivocal and in allcases the total volume of work was similar between groups.The present study was unique because, by design, the totaltraining volume for the SIT group was only ∼10% thatof the ET group (i.e. 630 versus 6500 kJ). In addition, thetotal training time commitment over 2 weeks was ∼2.5 hfor the SIT group (including the work intervals and therecovery periods between intervals), whereas the ET groupperformed continuous exercise each training day for a totalof ∼10.5 h. Thus, while previously speculated by others(Coyle, 2005), to our knowledge this is the first studyto demonstrate that SIT is indeed a very ‘time efficient’training strategy.

Effect of short-term sprint or endurance trainingon exercise performance

We are aware of only one previous study thatexamined changes in volitional exercise performance aftercontinuous or interval training. Eddy et al. (1977) hadsubjects perform cycle exercise training, 4 days per weekfor 7 weeks, using either a continuous (70% of VO2peak)or interval method (repeated 1 min bouts at 100% VO2peak

0

2

4

6

8

10PREPOST *

SIT ET

Figure 2. Maximal activity of COX measured in resting musclebiopsy samples obtained before (PRE) and after (POST)6 sessions of sprint interval training (SIT) or endurance training(ET) over 2 weeks∗P ≤ 0.05 versus pre-training (main effect for time). Lines denoteindividual data for 8 subjects in each group.

followed by 1 min of rest). The daily workload was matchedbetween groups and increased progressively from ∼100 kJper session during week 1 to ∼275 kJ per session duringweek 7. After training, subjects in both groups showedsimilar improvements during a matched-work exercisetest, such that cycling time to exhaustion at 90% of VO2peak

increased by an almost identical amount (∼26 min) inboth the continuous and interval groups. In the presentstudy, subjects performed 50 and 750 kJ cycling timetrials, which demanded work intensities equivalent to∼120 and ∼65% of peak power output elicited duringthe VO2peak tests. Consistent with the work of Eddyet al. (1977), subjects in the interval and continuoustraining groups showed remarkably similar improvementsin exercise performance. However, whereas Eddy et al.(1977) employed matched-work training protocols, the

S3 (SIT) S11 (ET)

Pre Post Pre Post

COX II

COX IV

0

1000

2000

3000

4000PREPOST *

SIT END

0

2000

4000

6000

8000

10000

12000PREPOST *

SIT END

Figure 3. Protein content of COX subunit II (middle panel) andIV (bottom panel) measured in resting muscle biopsy samplesobtained before (PRE) and after (POST) 6 sessions of sprintinterval training (SIT) or endurance training (ET) over 2 weeks∗P ≤ 0.05 versus pre-training (main effect for time). A representativeWestern blot (top panel) based on one subject from each group is alsopresented for each subunit. Lines denote individual data for 8 subjectsin each group.



Activité Cytochrome C oxidase

Protéines mitochondriales Aucune différence entre les groupes malgré le volume d’entraînement ≠

* P < 0,05

Pouvoir tampon ≈


* P < 0,05


Table 4. mRNA data

mRNA SIT group ET group

Pre-TR Post-TR Pre-TR Post-TR

COX II 0.84 ± 0.06 0.89 ± 0.04 0.79 ± 0.05 0.79 ± 0.04COX IV 0.0053 ± 0.0004 0.0072 ± 0.0010 0.0061 ± 0.0009 0.0048 ± 0.0008

SIT, sprint interval training; ET, endurance training; COX, cytochrome oxidase.

SIT group in the present study performed only 2–3 minof intense exercise per training session (which lasted18–27 min in total, including recovery periods betweenintervals), whereas the ET group performed 90–120 minof continuous exercise per session. While there was nocontrol group in the present study, recent work fromour laboratory has shown that control subjects drawnfrom the same population show no change in cycleendurance capacity (Burgomaster et al. 2005) or timetrial performance (Burgomaster et al. 2006) when tested∼2 weeks apart with no training intervention.

Rapid muscle adaptations induced by sprint orendurance training

Obviously, the factors responsible for training-inducedimprovements in exercise capacity are extremely complexand determined by numerous physiological (e.g.cardiovascular, muscle metabolic, neural, respiratory,thermoregulatory) and psychological attributes (e.g.mood, motivation, perception of effort). We assessedchanges in two parameters – muscle oxidative capacityand muscle buffering capacity – that are related to exercisetolerance (Hawley, 2002) and thus may have contributedto the observed improvement in time trial performance.Surprisingly, only a few previous studies have directlycompared changes in mitochondrial capacity after intervalor continuous training, and all employed matched-worktraining protocols that lasted several weeks (Henriksson& Reitman, 1976; Saltin et al. 1976; Fournier et al. 1982;

0

PRE

SIT ET

POST *

140150160170180190200210220

Figure 4. Skeletal muscle buffering capacity measured inresting muscle biopsy samples before (PRE) and after (POST)6 sessions of sprint interval training (SIT) or endurance training(ET) over 2 weeks∗P ≤ 0.05 versus pre-training (main effect for time). Lines denoteindividual data for 8 subjects in each group.

Gorostiaga et al. 1991). The results from these studiesare equivocal, with two studies reporting similar increasesin the maximal activities of mitochondrial enzymes afterinterval and continuous training (Henriksson & Reitman,1976; Saltin et al. 1976), while two others reportedincreases after continuous training only (Fournier et al.1982; Gorostiaga et al. 1991). The present study is the firstto directly compare changes in muscle oxidative capacityafter low-volume SIT and high-volume ET.

In accordance with one of our hypotheses, we observeda training-induced increase in the maximal activityof COX and the protein contents of COX subunits IIand IV, but there were no differences between groupsdespite the marked differences in training volume. Thepresent findings are consistent with recent work fromour laboratory that showed muscle oxidative capacitywas increased after a SIT protocol similar to that usedin the present study, or ∼15 min of intense exerciseover six training sessions in 2 weeks (Burgomaster et al.2005, 2006). While the time course for mitochondrialadaptations after short-term aerobic exercise training isequivocal (Green et al. 1992; Putman et al. 1998), ourresults are consistent with data from many laboratoriesshowing increases in oxidative enzymes after six toseven sessions of prolonged moderate intensity exercise(Spina et al. 1996; Chesley et al. 1996; Green et al. 1999;Starrit et al. 1999; Youngren et al. 2001). Finally, while thedesign of the present human study was unique, our data aresupported by previous work on rats that examined muscleadaptations to various forms of exercise training (Dudley

0100200300400500600700 PRE

SIT ET

POST *

Figure 5. Resting muscle glycogen content before (PRE) andafter (POST) 6 sessions of sprint interval training (SIT) orendurance training (ET) over 2 weeks∗P ≤ 0.05 versus pre-training (main effect for time). Lines denoteindividual data for 7 subjects in SIT group and 8 subjects in ET group.



+ 7,6 % + 4,2 %

En résumé,

•  SIT : stratégie d’entraînement + efficace (temps) –  Volume d’entraînement total (∼10% du protocole ET, 630 vs. 6500 kJ)

–  Temps d’entraînement total (2,5 h vs. 10,5 h pendant 2 semaines)

•  2 modalités d’entraînement avec les mêmes résultats posi+fs en 2 semaines (tolérance à l’exercice et performance ++) –  Ajustements physiologiques différents entre SIT (Δ rapide) et ET (Δ lent) guidés par la nature du s+mulus ?

Adapta+ons énergé+ques

Burgomaster et al. (2008)

6 semaines entraînement SIT vs. MICT chez 20 sujets actifs 23 ± 1 ans, VO2pic = 3,0 ± 0,2 l/min

J Physiol 586.1 Metabolic adaptations to sprint or endurance training in humans 153

Table 2. Summary of sprint interval training (SIT) and endurance training (ET)protocols

Variable SIT Group (n = 10) ET Group (n = 10)

Protocol 30 s × 4–6 repeats, 4.5 min rest 40–60 min cycling(3 × per week) (5 × per week)

Training intensity ‘All out’ maximal effort 65% of VO2peak

(workload) (∼500 W) (∼150 W)Weekly training ∼10 min ∼4.5 htime commitment (∼1.5 h including rest)Weekly training volume ∼225 kJ ∼2250 kJ

VO2peak, peak oxygen uptake.

Experimental protocol

Each subject served as their own control and performedtwo experimental trials, before and after a 6 week exercisetraining programme (see below). Upon arrival at thelaboratory, the lateral portion of one thigh was preparedfor the extraction of needle biopsy samples from the vastuslateralis muscle (Bergstrom, 1975). Two small incisionswere made in the skin and overlying fascia after injection ofa local anaesthetic (2% lidocaine). A biopsy was obtainedat rest, and then subjects commenced cycling for 60 minon an electronically braked cycle ergometer (Lode BV) ata workload designed to elicit ∼65% of pretraining VO2peak.Heart rate was determined using telemetry (Polar Electro,Woodbury, NY, USA) and expired gases were collected forthe determination of VO2 , VCO2 and respiratory exchangeratio (RER) using a metabolic cart (Moxus Modular VO2

System) and used to estimate rates of whole-body fat andcarbohydrate oxidation (Peronnet & Massicotte, 1991).A second muscle biopsy was obtained immediately afterexercise. The second experimental trial was performed 96 hafter the final exercise training session and was identical inall respects to the first experimental trial, including poweroutput which was set at the same absolute workload (i.e.65% of pretraining VO2peak).

Training protocol

The training protocols were initiated several days afterthe first experimental trial (Table 2). ET consistedof continuous cycling on an ergometer, 5 days perweek (Monday–Friday) for 6 weeks, at a power outputcorresponding to ∼65% VO2peak. Subjects performed40 min of exercise per training session for the first 2 weeks.Exercise time was increased to 50 min per session duringweeks 3 and 4, and subjects performed 60 min of exerciseper session during the final 2 weeks. VO2peak tests werere-administered after 3 weeks of training and trainingloads were adjusted in order to maintain a trainingintensity equivalent to ∼65% VO2peak. SIT consisted ofrepeated Wingate Tests on an ergometer 3 days per week(Monday, Wednesday and Friday) for 6 weeks. The number

of Wingate Tests performed during each training sessionincreased from four during week 1–2, to five during week3–4, and finally to six during week 5–6. For all trainingsessions, the recovery interval between Wingate Tests wasfixed at 4.5 min, during which time subjects cycled at alow cadence (< 50 r.p.m.) against a light resistance (30 W)to reduce venous pooling in the lower extremities andminimize feelings of light-headedness or nausea. Theendurance training programme was based on generalguidelines recommended by leading public health agencies(American College of Sports Medicine, 1998) whereas theSIT programme was modelled on recent studies conductedin our laboratory that have examined metabolic andperformance adaptations to low-volume, high-intensityinterval training (Burgomaster et al. 2005, 2006, 2007;Gibala et al. 2006a). By design, the protocols differedsubstantially in terms of total exercise training volumeand time commitment in order to evaluate adaptationsin skeletal muscle metabolism to two diverse trainingprogrammes.

Dietary controls

Subjects were instructed to continue their normal dietaryand physical activity practices throughout the experimentbut to refrain from alcohol and exercise for 48 h before eachtrial. Exercise was performed 3 h after a standardized meal.Subjects recorded their dietary intake for 24 h prior to thepretrial so that their individual pattern of food intake couldbe replicated in the 24 h before the post-trial. Subsequentdietary analyses (Nutritionist Five, First Data Bank, SanBruno, CA, USA) revealed no differences in total energyintake or macronutrient composition prior to the two trialsand no differences between groups (Table 3).

Muscle analyses

Muscle samples were initially sectioned into severalpieces under liquid nitrogen and one of the pieceswas freeze-dried, powdered and dissected free of all



Pour les 2 groupes : gain de VO2pic, Puissance pic Pour le groupe SIT : gain Puissance moyenne (+7%)

Burgomaster et al. (2008)

Aucune différence entre les groupes

* P < 0,05

PRE POST Training 6 sem. 0 60 min 0 60 min

65% VO2pic PRE


* P < 0,05

En résumé,

•  SIT : stratégie d’entraînement + efficace (temps) –  Volume d’entraînement total 90% plus faible (∼225 vs. 22550 kJ)

–  Temps d’entraînement total 1/3 (1,5 h vs. 4,5 h) •  6 semaines SIT : adapta+ons comparables avec ET

–  Métabolismes lipidique et glucidique –  Contrôle métabolique à l’exercice

• Mécanismes moléculaires ? Biogénèse mitochondriale ≈

Adapta+ons Vasculaires

Rakobowchuk et al. (2008)

6 semaines entraînement SIT (4-6 Wingate – 4,5 min, 3 jours/sem.) vs. MICT (40-60 min 65% VO2pic, 5 jours/sem.) 20 sujets actifs 23 ± 3 ans, VO2pic = 3,0 ± 0,2 l/min

Artère poplitée

NS NS

Artère carotide

structure

Rakobowchuk et al. (2008)

Fonction endothéliale (poplitée)


* P < 0,05

SIT : stratégie efficace pour améliorer la structure et fonction vasculaire périphérique (comparable à ET)

Index (Hepple et al. 1997) -Nb capillaires autour d’une fibre : + 20% (ET) vs. + 21% (SIT) -Rapport capillaire/fibre : + 22% (ET) vs. +24% (SIT) -Densité capillaire : + 32% (ET) vs. +27% (SIT)

Capillarisation


J Physiol 591.3 Microvascular adaptations to training in sedentary males 651

Table 2. Capillarisation pre- and post-training

Endurance Sprint interval

Variable Pre-training Post-training Pre-training Post-training

FA (mm2) 5131 ± 525 4607 ± 398 4437 ± 172 4339 ± 332CC 5.07 ± 0.47 6.07 ± 0.55∗ 4.53 ± 0.23 5.50 ± 0.35∗

C/FI 1.90 ± 0.20 2.32 ± 0.23∗ 1.66 ± 0.10 2.07 ± 0.15∗

SF 2.69 ± 0.06 2.68 ± 0.03 2.78 ± 0.02 2.71 ± 0.03CD (caps mm−2) 663.0 ± 26.5 872.9 ± 33.6∗ 642.0 ± 34.2 816.3 ± 24.0∗

Values are means ± SEM. ∗P < 0.05, main effect of training. FA, fibre cross-sectional area; SF, sharing factor; CD, capillary density;CC, capillary contacts; C/FI, capillary-to-fibre ratio on an individual-fibre basis.

human skeletal muscle (Fig. 1) with a significantly largerincrease occurring following SIT (36%) than followingET (16%). The effect of ET in our study in humans isin line with previous work in rats showing that end-urance training increases the eNOS content, measuredwith Western blots applied to isolated second to fifthorder arterioles isolated from the gastrocnemius muscle(McAllister et al. 2005). This increase in eNOS contentmay potentially lead to increases in NO productionupon stimulation by insulin, exercise induced shear stress

and exercise induced VEGF production as previouslyhypothesised (Hood et al. 1998; Vincent et al. 2004;Wagenmakers et al. 2006; Spier et al. 2007). However,future studies making parallel measurements of eNOScontent, eNOS ser1177 phosphorylation and muscle micro-vascular blood volume and flow will be required to confirmthat higher eNOS content has functional consequences formuscle microvascular blood flow regulation.

The larger improvement in microvascular eNOScontent following SIT is in agreement with previous work

ET

SIT

Post training Pre training

Pre training Post training

Figure 4. Effects of endurance training (ET) and sprint interval training (SIT) on skeletal musclecapillarisationComposite widefield microscopy images of skeletal muscle pre- (left) and post- (right) endurance training (top)and sprint interval training (bottom). Skeletal muscle microvessels were visualised using Ulex europaeus–FITCconjugated lectin (green) and the skeletal muscle membrane was revealed using wheat germ agglutinin-350(blue). Bar = 50 µm.

C© 2013 The Authors. The Journal of Physiology C© 2013 The Physiological Society

SIT : stratégie efficace pour améliorer la fonction micro vasculaire (comparable à ET)

Perspective : bénéfices vasculaires - maladies chroniques?

HIT session. Each HIT session consisted of a 5-min warm-upfollowed by 1-min exercise at 120% of the pretraining WRmax

followed by 1-min “loadless” cycling. This interval was repeated 8times on training days 1 and 2 and progressed to 12 repeated intervalsby the eighth session. Subjects were given strong verbal encourage-ment, and resistive loads were altered in accordance with the averagepedal cadence to ensure that the average WR for each 1-min bout was120% of the pretraining WRmax.

END session. The END protocol was adapted from a protocoldescribed previously (22, 46). Briefly, each training session consistedof 90–120 min of cycling at an intensity equivalent to 65% of thepretraining VO2 max. Subjects were monitored by the investigators andgiven verbal encouragement when required. Subjects were allowedbrief rest pauses (30–90 s) if they were unable to perform the 90-minexercise continuously, as described by others (22). Average cadencewas recorded to allow calculation of average work completed persession and total work completed for the entire training program.

Dietary considerations. Subjects were asked to record their diet on theday before the RI and TTF performance tests and to replicate this samediet before the mid- and posttraining tests. Subjects were instructed toabstain from caffeine or alcohol for at least 8 h before testing.

Data Collection

Gas-exchange measurements were similar to those described pre-viously (55). Briefly, inspired and expired flow rates were measuredusing a low dead space (90 ml) bi-directional turbine (Alpha Tech-nologies VMM 110), which was calibrated before each test with theuse of a 3.0-liter syringe. Inspired and expired gases were sampledcontinuously at the mouth and analyzed for concentrations of O2,CO2, and N2 by mass spectrometry (Amis 2000, Innovision, Odense,Denmark) after calibration with precision-analyzed gas mixtures.Breath-by-breath alveolar gas exchange was calculated using thealgorithms of Beaver et al. (3). Beat-by-beat heart rate (HR) wasrecorded continuously by a three-lead electrocardiogram.

Local muscle oxygenation of the vastus lateralis muscle of thequadriceps muscle group was monitored by near-infrared spectros-copy (NIRS) (NIRO 300, Hamamatsu Photonics, Hamamatsu City,Japan) using the method described by DeLorey et al. (13). The theoryof NIRS is described in detail by Elwell (16). The inter-optodespacing was 5 cm, and the differential pathlength factor was assumedto be 3.83; however, because of the uncertainty of this value duringexercise, NIRS data are reported as “arbitrary units”. Changes in oxy-(!O2Hb), deoxy- (!HHb), and total-hemoglobin-myoglobin (!Hbtot)are reported as a change in concentration (in arbitrary units) from thepretransition (20 W cycling) baseline. The !HHb signal can beregarded as being essentially blood volume insensitive during exercise(10, 17); thus it was assumed to reflect muscle O2 extraction withinthe field of interrogation (11, 17).

Data Analysis

Curve fitting. Kinetic analysis of breath-by-breath VO2p, beat-by-beat HR, and NIRS-derived deoxygenation data have been describedpreviously (13, 23, 24, 40, 55). VO2p and HR data obtained duringeach step transition were filtered for aberrant data points and linearlyinterpolated to 1-s intervals. Each transition was time aligned andensemble averaged to yield a single profile and then averaged into10-s time bins to yield a single response for each subject at each of thefive testing periods (i.e., preperiod, 2 days of training, mid-period, 6days of training, postperiod). The phase 1-phase 2 transition wasidentified as previously described (24, 54). The fundamental phase IIVO2p kinetics was modeled using a monoexponential equation (Eq. 1)and nonlinear regression techniques:

Y"t# ! Y"BSL# " Amp $1 # e%"&t-TD/'#() (1)

where Y(t) represents the variable of interest at any time (t) during thetransition to exercise, Y(BSL) is the starting baseline value of Y, Amp

is the steady-state increase in Y above the baseline value, ' is the timeconstant (defined as the time required for Y to increase to a valueequivalent to 63% Amp), and TD is the time delay. VO2p and HR datawere fit from, respectively, the phase I-phase II transition and theonset of exercise to the end-exercise using Origin data fitting software(OriginLab).

NIRS-derived data from each step transition were time aligned,ensemble averaged, and time averaged into 5-s time bins to yield asingle response for each subject. The initial TD after exercise onsetbefore an increase in !HHb was seen (!HHbTD) was determined bysecond-by-second data and corresponded to the time of the first pointdemonstrating a consistent increase above the nadir of the !HHbsignal. The !HHb data between the !HHbTD and 90 s (correspondingto the duration of the phase II VO2p response) were modeled with amonoexponential function of the form given in Eq. 1 to determine thetime course of muscle !HHb ('!HHb). The effective time constant('* + !HHbTD , '!HHb) was calculated to provide a description ofthe overall time course for muscle !HHb.

Plasma [Lac&] analysis. Arterialized venous blood samples fromthe RI test were analyzed for plasma [Lac&] with an ion-selectiveelectrode (StatProfile 9 Plus blood gas-electrolyte analyzer, NovaBiomedical Canada). The electrodes were calibrated before each testand at regular intervals throughout the analysis.

Statistical Analysis

Statistical analysis was performed using SigmaStat 3.0 analysissoftware (Systat). Differences between groups for total and averagework completed during training were analyzed by one-way ANOVA.The parameter estimates for VO2p, HR, !HHb, !O2Hb, !Hbtot, peakexercise responses, [Lac&], and body mass were analyzed with atwo-way ANOVA for repeated measures (one factor for time and onefactor for training program). Correlations for 'VO2p vs. time and!'VO2p vs. pre-'VO2p were analyzed using the Pearson productmoment correlation. Statistical significance was accepted at P - 0.05.Significant interactions and main effects were analyzed using theTukey’s honestly significant difference post hoc test. All results arepresented as means . SD.

RESULTS

A descriptive summary of the two exercise training proto-cols used in this study is presented in Table 1. The totalexercise time for the eight training sessions was /90% lower(P - 0.001) in HIT (80 min) than in END (825 min), and thetotal exercise training volume in HIT (/1,800 kJ) was /80%lower (P - 0.001) than in END (/8,500 kJ).

Table 1. Training protocols

Parameter HIT END

Work intensity /120% VO2 max

(/390 W)/65% VO2 max (/175 W)

Exercise protocol 60 s 0 8–12 repeats,60 s rest betweeneach repetition

90–120 min

Total exercise time 80 min 825 min*Total time including rest 160 minExercise volume per

session/200 kJ /1,050 kJ*

Total exercise volume /1,800 kJ /8,500 kJ*

HIT, high-intensity interval training; END, continuous endurance training;VO2 max, maximal O2 uptake. Total exercise volume and exercise volume persession results are based on average workloads sustained during trainingsessions, excluding rest intervals (loadless cycling). *Significantly different(P - 0.001) from HIT.

130 HIGH-INTENSITY INTERVAL TRAINING, VO2, AND MUSCLE DEOXYGENATION KINETICS

J Appl Physiol • VOL 107 • JULY 2009 • www.jap.org

on March 23, 2015

Dow

nloaded from

Adapta+ons Cardiorespiratoire et Périphérique

McKay et al. (2009)

12 sujets adultes, 25 ± 4 ans, VO2max 3,7 ± 0,5 l/min

Test de fatigue (après 8 séances d’entraînement) : + 55% (HIT) vs. + 43 % (END)

60

Temps (sec) Con

som

mat

ion

d’ox

ygèn

e (l·

min

-1)

État stable

DEMANDE EN ATP

Exercice

Déficit en O2

τ : constante de temps (sec)

délai (sec)

~63% amplitude de la réponse (l·min-1)

Repos

Exercice constant

Cinétique de VO2p (exercise modéré)

McKay et al. (2009) Aucune différence entre les groupes P < 0,05

Amélioration de l’utilisation de l’O2

Bailey et al. (2009)

3 groupes 6 séances (2 semaines) SIT (RST = 4-7 x 30 s, 4 min) vs. ET (charge équilibrée) vs. CONT Total : 126 min ET 17,5 min RST

Cinétique de VO2p

“intensité modérée”

24 sujets adultes, 21 ± 4 ans

Gain RST (test incrémental) : VO2pic + 8% et Puissance pic + 5%


Cinétique de VO2p

“intensité difficile”

Amélioration uniquement pour le groupe SIT : -Tolérance exercice -Cinétique de VO2

RST

ET


Cinétique oxygénation musculaire

“intensité difficile”

Groupe SIT Cinétiques corrélées (HHb – VO2) é extraction en O2

SIT

ET

MacPherson et al. (2011)

6 semaines : SIT (4-5 x 30 s all-out, course ; 4 min repos) vs. MICT (65% VO2max 30-60 min) 20 sujets, 24 ± 3 ans

Adapta+ons Cardiaques

* P < 0,05 Aucune différence entre les groupes

Séance 30 s

2000 m +5,9 % (-32 s)

+4,6 % (-25 s)

+12,5 % +11,5 %

*P < 0,05, Pre / Post †P < 0,05, Interaction

+9,5 %

-7,1 % +7,1 %

+10,4 %

Adaptations ≠ entre SIT & ET ET : centrales SIT : périphériques Perspective : intégration de SIT chez les athlètes d’endurance - population ‘générale’ ?

Mesure de la force de l’effet d de Cohen Faible (0,2) Modéré (0,5) Large (0,8)

SYSTEMATIC REVIEW

Sprint Interval Training Effects on Aerobic Capacity:A Systematic Review and Meta-Analysis

Nicholas H. Gist • Michael V. Fedewa •

Rod K. Dishman • Kirk J. Cureton

! Springer International Publishing Switzerland 2013

AbstractBackground Sprint interval training (SIT) involving

repeated 30-s ‘‘all out’’ efforts have resulted in significantly

improved skeletal muscle oxidative capacity, maximaloxygen uptake, and endurance performance. The positive

impact of SIT on cardiorespiratory fitness has far-reaching

health implications.Objective The objective of this study was to perform a

systematic review of the literature and meta-analysis to

determine the effects of SIT on aerobic capacity.Methods A search of the literature was conducted using

the key words ‘sprint interval training’, ‘high intensity

intermittent training/exercise’, ‘aerobic capacity’, and‘maximal oxygen uptake’. Seventeen effects were analyzed

from 16 randomized controlled trials of 318 participants.

The mean ± standard deviation number of participants was18.7 ± 5.1. Participant age was 23.5 ± 4.3 years.

Results The effect size calculated for all studies indicates

that supramaximal-intensity SIT has a small-to-moderateeffect (Cohen’s d = 0.32, 95 % CI 0.10–0.55; z = 2.79,

P \ 0.01) on aerobic capacity with an aggregateimprovement of *3.6 mL!kg-1!min-1 (*8 % increase).

The effect is moderate to large in comparison with no-

exercise control groups (Cohen’s d = 0.69, 95 % CI0.46–0.93; z = 5.84, P \ 0.01) and not different when

compared with endurance training control groups (Cohen’sd = 0.04, 95 % CI -0.17 to 0.24; z = 0.36, P = 0.72).

Conclusion SIT improves aerobic capacity in healthy,

young people. Relative to continuous endurance training ofmoderate intensity, SIT presents an equally effective

alternative with a reduced volume of activity. This evalu-

ation of effects and analysis of moderating variables con-solidates the findings of small-sample studies and

contributes to the practical application of SIT to improve

cardiorespiratory fitness and health.

1 Introduction

The development of new exercise interventions aimed at

reducing health problems (cardiovascular disease, hyper-

insulinemia, obesity, hypertriglyceridemia, and hyperten-sion) associated with physical inactivity is a far-reaching

research effort that holds great value. Epidemiological

studies have shown that low cardiorespiratory fitness isassociated with higher rates of cardiovascular disease,

type 2 diabetes mellitus, cancer, and all-cause mortality[1–6]. Cardiorespiratory fitness, typically assessed via a

measure of maximal oxygen uptake (VO2max), has a neg-

atively linear relationship with increasing age up to45 years, with reported declines of *8 % per decade with

accelerated reduction of up to 20 % per decade at age

70 years [7, 8]. In a meta-analysis including only studies ofwomen, the findings highlighted age-related decreases in

VO2max in both sedentary and previously active endurance

athletes [9]. The importance of improvement or attenuationof age-related decline in VO2max extends beyond athletic

performance.

Although high-intensity interval training (HIT) iscommonly used by elite athletes to enhance performance,

N. H. Gist ! M. V. Fedewa ! R. K. Dishman ! K. J. CuretonDepartment of Kinesiology, University of Georgia, Athens,GA, USA

N. H. Gist (&)Department of Physical Education, Arvin Cadet PhysicalDevelopment Center, United States Military Academy,727 Brewerton Road, West Point, NY 10996, USAe-mail: [email protected]

Sports Med

DOI 10.1007/s40279-013-0115-0

measure; (2) animal subjects; or (3) training intensity did

not meet the ‘‘supramaximal’’ or ‘‘maximal’’ threshold.

2.3 Study Selection

A search of electronic databases and a scan of article ref-

erence lists revealed 303 relevant studies (Fig. 1). Based on

a review of the title or abstract or lack of control group inthe experimental design, 264 articles were dismissed.

Forty-one full-text articles were evaluated, and 16 wereincluded for the meta-analysis. Each study was read and

coded for descriptive variables: country, age, sex, body

mass index, training status (sedentary, recreational, andtrained), type of control group (no exercise, endurance

training), control group exercise mode and intensity,

experimental group exercise mode and intensity, work:restratio, and length of intervention.

2.4 Data Collection

Aerobic capacity data were extracted in the forms of pre-

and post-training intervention means, standard deviations(SDs), and sample sizes for SIT and control conditions.

Dependent variables included VO2max or VO2peak reported

in mL!kg-1!min-1 or L!min-1 (if relative values were notreported). In studies that reported intermediate and post-

intervention values, only final values for aerobic capacity

were compared with baseline.

2.5 Study Characteristics

Seventeen effects were collected from 16 RCTs [16–19,28, 30, 31, 42–50] of 318 participants. Two effects were

calculated and included from a study by Bailey et al. [16]

because the experimental design included a sprint traininggroup, an endurance training group, and a no-exercise

control group, thus permitting a comparison of SIT to the

endurance training as well as the no-exercise controls.Study characteristics are presented as mean ± SD unless

otherwise stated. The number of participants was

18.7 ± 5.1. Participant age was 23.5 ± 4.3 years. Sixeffects involved studies of men only; four included

exclusively women; seven enrolled both men and women.

Aerobic capacity was a primary outcome for nine of thestudies. The mode of sprint exercise for interventions pri-

marily involved cycling (nine studies); six studies admin-

istered a sprint interval running protocol, and one studyused rowing. Training intervention length was

4.8 ± 2.3 weeks with 2.9 ± 0.4 sessions per week. There

were four studies conducted in Canada, four in the USA,two in the UK, two in Australia, two in Iran, one in Den-

mark, and one in Norway.

2.6 Meta-Analysis

To estimate the magnitude of the impact of SIT on VO2max,effect sizes (ES) were calculated as Cohen’s d by

Fig. 1 Flow chart of studyselection

Sprint Interval Training Effects on Aerobic Capacity

Méta-analyse

Le recours à la modalité SIT sur VO2max possède un effet :

•  Faible à modéré (amélioration de ∼8%), d = 0,32 •  Modéré à large (sans groupe contrôle), d = 0,69

•  Inexistant (en comparaison groupe ET), d = 0,04

SIT : une alternative avec un volume d’entraînement moindre

Adulte jeune (23,2 ± 4,3 ans) en bonne santé ; période d’entraînement < 6 sem. Adhésion ? Blessures ? Risques ?

Gist et al. (2014)

Engagement – Risques du SIT

Risques des protocoles à intensité supramaximale (Gaesser et Angadi, 2011) ; Adhésion à l’exercice (Ekkekakis et al., 2008)

Besoin d’optimiser les protocoles SIT

•  î Intensité exercice diminue les gains de VO2pic mais pas les adaptations mitochondriales (Boyd et al., 2013)

•  î Fréquence d’entraînement diminue le gain du seuil anaérobie (Dalleck et al., 2010)

•  î Durée exercice : pas d’effet sur adaptation capacité aérobie, performance en endurance (Hazell et al., 2010)

de 30 à 10 s : période suffisante pour améliorer les mécanismes sous-jacents à la performance aérobie (Bangsbo et al., 2009)

Bénéfices physiologiques reconnus MAIS application SIT questionnable pour une large population :

•  Motivation et engagement importants •  Exercice à intensité élevée : affect négatif (processus d’évitement) •  SIT : complexe avec degré élevé d'auto-régulation (barrière chez les

débutants)

OPINION ARTICLEpublished: 23 December 2014doi: 10.3389/fpsyg.2014.01505

Why sprint interval training is inappropriate for a largelysedentary populationSarah J. Hardcastle1*, Hannah Ray2, Louisa Beale2 and Martin S. Hagger1

1 Health Psychology and Behavioural Medicine Research Group, School of Psychology and Speech Pathology, Faculty of Health Sciences, Curtin University, Perth,WA, Australia

2 School of Sport and Service Management, University of Brighton, Eastbourne, UK*Correspondence: [email protected]

Edited by:Angelo Compare, University of Bergamo, Italy

Reviewed by:Agostino Brugnera, University of Bergamo, Italy

Keywords: exercise psychology, sprint interval training, exercise intensity, behavior-change, feeling states, exercise adherence

Public health practitioners and researchersin behavioral medicine recognize the needto find effective physical activity inter-ventions and prescriptions to curb thegrowth in inactivity and prevent chronicillness (Conn et al., 2009; Hagger, 2010;Hardcastle et al., 2012; Katzmarzyk andLear, 2012). For example, researchers inexercise physiology have focused on theminimal dose of exercise needed to gainfavorable physiological adaptations to car-diovascular and metabolic systems (Gibalaet al., 2012). Efforts to identify a min-imal dose of exercise are linked to theproblem of exercise adherence with fewpeople meeting current physical activityguidelines of 30 min per day of moder-ate intensity exercise. Given that time isthe most commonly cited barrier to exer-cise (Trost et al., 2002; Sequeira et al.,2011), exercise professionals have focusedattention on the development of time-efficient exercise interventions (Gibala,2007). A recent development is the advo-cacy of Sprint Interval Training (SIT) asa means to attain substantial health ben-efits with a lower overall exercise vol-ume. SIT is characterized by repeated,brief (4–6 × <30 s), intermittent burstsof all-out exercise, interspersed by peri-ods (approximately 4.5 min) of active orpassive recovery (Gibala et al., 2012).Research has consistently demonstratedthat participation in SIT results in ahost of physiological adaptations includ-ing improvements in health and fitnessindicators (Burgomaster et al., 2006, 2008;Gibala et al., 2006, 2012; Rossow et al.,2010; Tong et al., 2011). In addition, these

improvements have been reported to beequal or superior to traditional continu-ous aerobic training despite SIT involvinga substantially lower total overall trainingvolume (Rossow et al., 2010; Tong et al.,2011; Gibala et al., 2012; Cocks et al.,2013). Consequently, SIT is being advo-cated as a time-efficient alternative inter-vention for the achievement of fitness andhealth benefits through exercise (Gibala,2007; Whyte et al., 2013).

In this article we contend that SIT isunlikely to be taken up by the majorityof the sedentary population and cautionis needed before such training is advo-cated to the general public. Proponentsof SIT have focused almost exclusively onphysiological adaptations. However, theexclusive focus fails to consider whethera largely sedentary population will feelphysically capable and sufficiently moti-vated to take up and maintain a regimeof highly intense exercise. Based on the-ory and research in exercise psychology, wecontend that the prospect of participatingin SIT for previously sedentary individualsis likely to be considered too arduous andmay evoke anticipated perceived incom-petence, lower self-esteem, and potentialfailure (Williams and Gill, 1995; Heinand Hagger, 2007; Lindwall et al., 2011).They may likely be more inclined to avoidparticipating as a consequence. We alsocontend that should previously sedentaryindividuals be introduced to high inten-sity exercise of the type proposed in SITit will likely evoke a high degree of neg-ative affect that may lead to an avoidantresponse with the prospect of future

sessions. In addition, we contend that SITis a complex and structured regime thatrequires high levels of self-discipline andself-regulation and is, therefore, unlikelyto be adopted outside the laboratoryenvironment (Hagger, 2013; Hagger andLuszczynska, 2014). Finally, we debate thenotion that SIT is time-efficient and sug-gest that it does not sufficiently address“lack of time” as a commonly-cited bar-rier to exercise (Hardcastle and Hagger,2011).

In a largely sedentary population, thestrenuous nature of SIT is likely to bea deterrent to participation because indi-viduals tend to avoid exercise if theyfind it aversive. Several theories includingsocial cognitive theory (Bandura, 1977),achievement motivation theory (Weiner,1985) and self-determination theory (Deciand Ryan, 1985; Hagger et al., 2006;Chatzisarantis et al., 2007) contend thata high level of motivation and compe-tence are needed to participate in regu-lar physical activity. Typically, sedentaryand low-active individuals do not feelcompetent in the physical domain andmay not, therefore, feel sufficiently con-fident to engage in the activity (Teixeiraet al., 2012). The motivation and effortrequired to participate in high inten-sity exercise is much higher than thatneeded to undertake activities of a moder-ate intensity (e.g. walking) (Williams andGill, 1995; Tritter et al., 2013). If indi-viduals feel unable to demonstrate com-petence in SIT, they are more likely toinvest little effort in a prescribed activityor avoid it all together. Low competence,

www.frontiersin.org December 2014 | Volume 5 | Article 1505 | 1

Conclusion

ì Puissance Aérobie … et Anaérobie

SIT W: 4-‐6 x < 30s, R:

<4 min

ì  Activité enzymes oxydatives ì  Capacité tampon

ì  biogénèse mitochondriale ì  PGC-1 alpha

Stratégie efficace (80-90% de temps gagné) pour des adaptations presque similaires à court terme

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