Effects of resistance exercise combined with essential amino acid supplementation and energy deficit on markers of skeletal muscle atrophy and regeneration during bed rest and active recovery

Abstract

INTRODUCTION Space flight and bed rest (BR) lead to muscle atrophy. This study assessed the effect of essential amino acid supplementation (EAA) and resistance training with decreased energy intake on molecular changes in skeletal muscle after 28d BR and 14d recovery. METHODS Thirty-one men (31–55yr) subjected to an 8±6% energy deficit were randomized to receive EAA without resistance training (AA, n=7), EAA 3 h after (RT, n=12), or 5 min before (AART, n=12) resistance training. RESULTS During BR, myostatin transcript levels increased 2-fold in the AA group. During recovery, IGF1 mRNA increased in all groups while Pax7, MyoD, myogenin and MRF4 transcripts increased in AA only (all p<0.05). MAFbx transcripts decreased 2-fold with AA and RT. Satellite cells did not change during BR or recovery. DISCUSSION This suggests that EAA alone is the least protective countermeasure to muscle loss, and several molecular mechanisms are proposed by which exercise attenuates muscle atrophy during bed rest with energy deficit.

Exercises of Lumbar Stabilizer Muscles, Resistance Training, and Soy Food Consumption: A Comparative Study Between Old and Young Women

“…Numerous studies have been conducted in line with the present study [9] and improved capability and increased waist multifidus muscle cross-sectional area have been reported [9]. Old people respond to sports-dietary interventions slower than young people due to anabolic resistance and disruption of anabolic routes [8,9,14]. Hence, regular consumption of soy milk, along with exercise [8] and slow performance of exercises, improve proteolytic routes and muscular hypertrophy in old people [14].…”

“…Old people respond to sports-dietary interventions slower than young people due to anabolic resistance and disruption of anabolic routes [8,9,14]. Hence, regular consumption of soy milk, along with exercise [8] and slow performance of exercises, improve proteolytic routes and muscular hypertrophy in old people [14]. Lack of soy milk group and the failure to perform exercises by young women were among the limitations of this study.…”

“…Lumbar stabilization exercises [13,14] included boat, shoulder flexion in the horizontal axis, back to ground push-ups, sit-up, wheel pose, back extension (prone), hip flexion (supine), and shoulder flexion (standing). In order to respect the principle of overload, traband (training boat, shoulder flexion, hip flexion), free weights (sit-up, wheel pose, waist extension, shoulder flexion), and sphygmomanometer (back to ground push-up) were used and the intensity of exercise was increased while creating compatibility (Borg scale 8 or less).…”

“…In order to respect the principle of overload, traband (training boat, shoulder flexion, hip flexion), free weights (sit-up, wheel pose, waist extension, shoulder flexion), and sphygmomanometer (back to ground push-up) were used and the intensity of exercise was increased while creating compatibility (Borg scale 8 or less). Cross-sectional area of multifidus muscle was examined in the fourth lumbar vertebra by sonography device (Italy) [14]. Data normalization was examined by Shapiro-Francia test, and the equality of variances was evaluated by Levene's test.…”

Calcium kinetics during bed rest with artificial gravity and exercise countermeasures

“…Details of this study have been published [17, 20]. The study consisted of a 9-day baseline period followed by a 28-day period of horizontal bed rest.…”