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Jacobs 2013 Abstract MiP2013

From Bioblast
Jacobs RA, Flรผck D, Bonne TC, Bรผrgi S, Christensen PM, Toigo M, Lundby C (2013) Improvements in exercise performance with high-intensity interval training are facilitated by an increase in skeletal muscle mitochondria content. Mitochondr Physiol Network 18.08.

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Jacobs RA, Flueck D, Bonne TC, Buergi S, Christensen PM, Toigo M, Lundby C (2013)

Event: MiP2013

Six sessions of high-intensity interval training (HIT) completed over a two-week span is sufficient to improve exercise capacity [1,2]. The mechanisms explaining such improvements are not fully understood. Accordingly, the aim of the present study was to perform a comprehensive evaluation of physiologically relevant adaptations occurring after 6 sessions of HIT in sedentary young adults and determine the mechanisms explaining improvements in exercise performance. Sixteen sedentary subjects completed 6 sessions of repeated [8-12] 60 s intervals of high-intensity cycling (100% peak power output elicited during incremental maximal exercise test) intermixed with 90 s of recovery cycling at a low intensity (30 W) over a 2-week period. Potential training-induced alterations in skeletal muscle respiratory capacity, mitochondrial content, skeletal muscle oxygenation, cardiac capacity, blood volumes, and peripheral fatigue resistance were assessed. Training improved maximal oxygen consumption (VO2max; ~8%; p=0.026) and cycling time to complete a set amount of work (~5%; p=0.008). Skeletal muscle respiratory capacity improved, most likely as a result of an increased content of skeletal muscle mitochondria (~20%, p=0.026). Maximal tissue oxygenation improved by 10% while maximal cardiac output, blood volumes, oxygen carrying capacity, and relative measures of peripheral fatigue resistance were all unaltered with training. These results suggest that acute increases in mitochondrial content following two-weeks of HIT may facilitate improvements in respiratory capacity, tissue oxygenation, and ultimately are responsible for the improvements in both maximal whole-body exercise capacity as well as endurance performance in previously sedentary individuals.


โ€ข O2k-Network Lab: CH Zurich Lundby C


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Organism: Human 







Affiliations and author contributions

1 - Zurich Center for Integrative Human Physiology (ZIHP); 2 - Institute of Physiology, University of Zurich, Switzerland; 3 - Department of Exercise and Sport Sciences, University of Copenhagen, Denmark; 4 - Exercise Physiology, Institute of Human Movement Sciences, ETH Zurich, Switzerland.

Email: [email protected]

References

  1. Burgomaster KA, Hughes SC, Heigenhauser GJ, Bradwell SN, and Gibala MJ (2005) Six sessions of sprint interval training increases muscle oxidative potential and cycle endurance capacity in humans. J Appl Physiol 98:1985-1990.
  2. Talanian JL, Holloway GP, Snook LA, Heigenhauser GJ, Bonen A, and Spriet LL (2010) Exercise training increases sarcolemmal and mitochondrial fatty acid transport proteins in human skeletal muscle. Am J Physiol Endocrinol Metab 299: E180-188.