Effects of pre-exercise feeding on serum hormone concentrations and biomarkers of myostatin and ubiquitin proteasome pathway activity
- 649 Downloads
The aim of the study was to examine the acute effects of pre-exercise ingestion of protein, carbohydrate, and a non-caloric placebo on serum concentrations of insulin and cortisol, and the intramuscular gene expression of myostatin- and ubiquitin proteasome pathway (UPP)-related genes following a bout of resistance exercise.
Ten untrained college-aged men participated in three resistance exercise sessions (3 × 10 at 80 % 1RM for bilateral hack squat, leg press, and leg extension) in a cross-over fashion, which were randomly preceded by protein, carbohydrate, or placebo ingestion 30 min prior to training. Pre-supplement/pre-exercise, 2 h and 6 h post-exercise muscle biopsies were obtained during each session and analyzed for mRNA fold changes in myostatin (MSTN), activin IIB, follistatin-like 3 (FSTL3), SMAD specific E3 ubiquitin protein ligase 1 (SMURF1), forkhead box O3, F-box protein 32 (FBXO32), and Muscle RING-finger protein-1, with beta-actin serving as the housekeeping gene. Gene expression of all genes was analyzed using real-time PCR.
Acute feeding appeared to have no significant effect on myostatin or UPP biomarkers. However, resistance exercise resulted in a significant downregulation of MSTN and FBXO32 mRNA expression and a significant upregulation in FSTL3 and SMURF1 mRNA expression (p < 0.05).
An acute bout of resistance exercise results in acute post-exercise alterations in intramuscular mRNA expression of myostatin and UPP markers suggestive of skeletal muscle growth. However, carbohydrate and protein feeding surrounding resistance exercise appear to have little influence on the acute expression of these markers.
KeywordsHypertrophy Strength Insulin Cortisol Protein
We would like to thank the subjects who participated in this study as well as all laboratory assistants who assisted with data collection and analysis. We would also like to graciously thank the reviewers who took time to critique this manuscript.
Conflict of interest
The authors have no competing interests.
- 8.Kraemer WJ, Hakkinen K, Newton RU et al (1999) Effects of heavy-resistance training on hormonal response patterns in younger vs. older men. J Appl Physiol 87(3):982–992Google Scholar
- 11.Volpi E, Kobayashi H, Sheffield-Moore M et al (2003) Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults. Am J Clin Nutr 78(2):250–258Google Scholar
- 17.Hartman JW, Tang JE, Wilkinson SB et al (2007) Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters. Am J Clin Nutr 86(2):373–381Google Scholar
- 18.Wilkinson SB, Tarnopolsky MA, Macdonald MJ et al (2007) Consumption of fluid skim milk promotes greater muscle protein accretion after resistance exercise than does consumption of an isonitrogenous and isoenergetic soy-protein beverage. Am J Clin Nutr 85(4):1031–1040Google Scholar
- 32.Baechle T, Earle R (2000) Essentials of strength and conditioning, 2nd edn. Human Kinetics, ChampaignGoogle Scholar
- 41.Fry AC, Lohnes CA (2010) Acute testosterone and cortisol responses to high power resistance exercise. Fiziol Cheloveka 36(4):102–106Google Scholar
- 51.Candow DG, Burke NC, Smith-Palmer T et al (2006) Effect of whey and soy protein supplementation combined with resistance training in young adults. Int J Sport Nutr Exerc Metab 16(3):233–244Google Scholar