Arginine and Ornithine Supplementation Increases Growth Hormone and Insulin-Like Growth Factor-1 Serum Levels After Heavy-Resistance Exercise in Strength-Trained Athletes

• Published in: Journal of strength and conditioning research Vol. 24; no. 4; pp. 1082 - 1090
• Main Authors: Zajac, Adam, Poprzęcki, Stanisław, Żebrowska, Aleksandra, Chalimoniuk, Małgorzata, Langfort, Jozef
• Format: Journal Article
• Language: English
• Published: United States National Strength and Conditioning Association 01-04-2010; Lippincott Williams & Wilkins Ovid Technologies
• Subjects: Administration, Oral; Analysis of Variance; Anthropometry; Arginine - administration & dosage; Athletes; Athletic Performance; Body Mass Index; Dietary Supplements; Double-Blind Method; Growth Hormone - blood; Growth Hormone - drug effects; Growth hormones; Humans; Insulin-Like Growth Factor I - drug effects; Insulin-Like Growth Factor I - metabolism; Male; Muscle Strength - drug effects; Muscle Strength - physiology; Nitric oxide; Ornithine - administration & dosage; Physical Endurance - drug effects; Physical Endurance - physiology; Plasma; Resistance Training - methods; Sports training; Testosterone; Wound healing; Young Adult
• ISSN: 1064-8011; 1533-4287
• DOI: 10.1519/JSC.0b013e3181d321ff

Zając, A, Poprzęcki, S, Żebrowska, A, Chalimoniuk, M, and Langfort, J. Arginine and ornithine supplementation increases GH and IGF-1 serum levels after heavy-resistance exercise in strength-trained athletes. J Strength Cond Res 24(4)1082-1090, 2010-This placebo-controlled double-blind study was designed to investigate the effect of arginine and ornithine (arg and orn) supplementation during 3-week heavy-resistance training on serum growth hormone/insulin-like growth factor-1/insulin-like growth factor-binding protein 3 (GH/IGF-1/IGFBP-3), testosterone, cortisol, and insulin levels in experienced strength-trained athletes. The subjects were randomly divided between a placebo group (n = 8) and the l-Arg/l-Orn-supplemented group (n = 9), and performed pre and posttraining standard exercise tests with the same absolute load, which consisted of the same exercise schedule as that applied in the training process. Fasting blood samples were obtained at rest, 2 minutes after the cessation of the strength exercise protocol, and after 1 hour of recovery. The resting concentrations of the investigated hormones and IGFBP-3 did not differ significantly between the study groups. In response to exercise test, all the hormones were elevated (p < 0.05) at both time points. Significant increases (p < 0.05) were observed in both GH and IGF-1 serum levels after arg and orn supplementation at both time points, whereas a significant decrease was seen in IGFBP-3 protein during the recovery period. Because there was no between-group difference in the remaining hormone levels, it appears that the GH/IGF-1/IGFBP-3 complex may be the major player in muscle tissue response to short-term resistance training after arg and orn supplementation.