Article

Skeletal muscle adaptation and performance responses to once a day versus twice every second day endurance training regimens

Exercise Metabolism Group, School of Medical Sciences, Bldg. 223.2.52, RMIT University, PO Box 71, Bundoora, Victoria 3083, Australia.
Journal of Applied Physiology (Impact Factor: 3.06). 09/2008; 105(5):1462-70. DOI: 10.1152/japplphysiol.90882.2008
Source: PubMed

ABSTRACT

We determined the effects of a cycle training program in which selected sessions were performed with low muscle glycogen content on training capacity and subsequent endurance performance, whole body substrate oxidation during submaximal exercise, and several mitochondrial enzymes and signaling proteins with putative roles in promoting training adaptation. Seven endurance-trained cyclists/triathletes trained daily (High) alternating between 100-min steady-state aerobic rides (AT) one day, followed by a high-intensity interval training session (HIT; 8 x 5 min at maximum self-selected effort) the next day. Another seven subjects trained twice every second day (Low), first undertaking AT, then 1-2 h later, the HIT. These training schedules were maintained for 3 wk. Forty-eight hours before and after the first and last training sessions, all subjects completed a 60-min steady-state ride (60SS) followed by a 60-min performance trial. Muscle biopsies were taken before and after 60SS, and rates of substrate oxidation were determined throughout this ride. Resting muscle glycogen concentration (412 +/- 51 vs. 577 +/- 34 micromol/g dry wt), rates of whole body fat oxidation during 60SS (1,261 +/- 247 vs. 1,698 +/- 174 micromol.kg(-1).60 min(-1)), the maximal activities of citrate synthase (45 +/- 2 vs. 54 +/- 1 mmol.kg dry wt(-1).min(-1)), and beta-hydroxyacyl-CoA-dehydrogenase (18 +/- 2 vs. 23 +/- 2 mmol.kg dry wt(-1).min(-1)) along with the total protein content of cytochrome c oxidase subunit IV were increased only in Low (all P < 0.05). Mitochondrial DNA content and peroxisome proliferator-activated receptor-gamma coactivator-1alpha protein levels were unchanged in both groups after training. Cycling performance improved by approximately 10% in both Low and High. We conclude that compared with training daily, training twice every second day compromised high-intensity training capacity. While selected markers of training adaptation were enhanced with twice a day training, the performance of a 1-h time trial undertaken after a 60-min steady-state ride was similar after once daily or twice every second day training programs.

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    • "Cet effet était associé à des réserves en glycogène musculaire plus élevées et une augmentation de l'activité des enzymes mitochondriales (HAD et CS) à la fin du programme d'entraînement pour le groupe Low. Par la suite, Yeo et al. [11], sur la base du protocole d'entraînement initié par Hansen et al., étudièrent l'effet de la réduction de la disponibilité en glucides pour des exercices impliquant le corps entier en alternant des séances de cyclisme à faible intensité (100 min à 70 % ˙ VO 2peak ) avec des sessions à haute intensité (8 × 5 min à intensité maximale, 1 min de récupération entre chaque série) sur une période de trois semaines chez des cyclistes/triathlètes entraînés. Dans cette étude, la performance mesurée par la puissance développée au cours d'un effort sur ergomètre d'une heure n'était pas différente entre les deux groupes (Low : 12,2 ± 2,3 % vs High : 10,2 ± 3,1 %). "

    Full-text · Dataset · Oct 2015
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    • "Cet effet était associé à des réserves en glycogène musculaire plus élevées et une augmentation de l'activité des enzymes mitochondriales (HAD et CS) à la fin du programme d'entraînement pour le groupe Low. Par la suite, Yeo et al. [11], sur la base du protocole d'entraînement initié par Hansen et al., étudièrent l'effet de la réduction de la disponibilité en glucides pour des exercices impliquant le corps entier en alternant des séances de cyclisme à faible intensité (100 min à 70 % ˙ VO 2peak ) avec des sessions à haute intensité (8 × 5 min à intensité maximale, 1 min de récupération entre chaque série) sur une période de trois semaines chez des cyclistes/triathlètes entraînés. Dans cette étude, la performance mesurée par la puissance développée au cours d'un effort sur ergomètre d'une heure n'était pas différente entre les deux groupes (Low : 12,2 ± 2,3 % vs High : 10,2 ± 3,1 %). "
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    • "After 10 weeks of training time to exhaustion at 90% power output was increased in the twice-a-day leg only (294 vs. 113%, respectively). Similarly, trained men cycling twice every second day compared to once every day for 3 weeks, showed increased glycogen storage, fat oxidation and mitochondrial enzyme activity, although no improvement in performance was found (Yeo et al. 2008). Only a few studies have investigated the effect of CHO restriction during recovery. "
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