The Effect of Strength Training and Consumption of Glutamine Supplement on GH/IGF1 Axis
Physical activity and diet are factors that influence the body's structure. The purpose of this study was to compare the effects of four weeks of resistance training, and glutamine supplement consumption on growth hormone (GH), and Insulin-like growth factor 1 (IGF-1) Axis. 40 amateur male bodybuilders, participated in this study. They were randomly divided into four equal groups, Resistance (R), Glutamine (G), Resistance with Glutamine (RG), and Control (C). The R group was assigned to a four week resistance training program, three times/week, three sets of 10 exercises with 6-10 repetitions, at the 80-95% 1RM (One Repetition Maximum), with 120 seconds rest between sets), G group is consuming l-glutamine (0.1 g/kg-1/day-1), RG group resistance training with consuming L-glutamine, and C group continued their normal lifestyle without exercise training. GH, IGF1, IGFBP-III plasma levels were measured before and after the protocol. One-way ANOVA indicated significant change in GH, IGF, and IGFBP-III between the four groups, and the Tukey test demonstrated significant increase in GH, IGF1, IGFBP-III plasma levels in R, and RG group. Based upon these findings, we concluded that resistance training at 80-95% 1RM intensity, and resistance training along with oral glutamine shows significantly increase secretion of GH, IGF-1, and IGFBP-III in amateur males, but the addition of oral glutamine to the exercise program did not show significant difference in GH, IGF-1, and IGFBP-III.
 Phillips S. M. A. brief review of critical processes in exercise-induced muscular hypertrophy. Sports Med 2014;44:71-77.
 Glaser S., Friedrich N., Ewert R., et al. Association of circulating IGF-I and IGFBP-3 concentrations and exercise capacity in healthy volunteers: results of the Study of Health in Pomerania. Growth Horm IGF Res 2010;20:404-410.
 Laron Z. Insulin-like growth factor 1 (IGF-1): a growth hormone. Molecular pathology : MP 2001;54:311-316.
 Philippou A., Maridaki M., Halapas A., Koutsilieris M. The role of the insulin-like growth factor 1 (IGF-1) in skeletal muscle physiology. In Vivo 2007;21:45-54.
 Juul A., Dalgaard P., Blum W. F., et al. Serum levels of insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) in healthy infants, children, and adolescents: the relation to IGF-I, IGF-II, IGFBP-1, IGFBP-2, age, sex, body mass index, and pubertal maturation. J Clin Endocrinol Metab 1995;80:2534-2542.
 Boelens P. G., Nijveldt R. J., Houdijk A. P., et al. Glutamine alimentation in catabolic state. The Journal of nutrition 2001;131:2569S-2577S; discussion 90S.
 Koo G. H., Woo J., Kang S., et al. Effects of Supplementation with BCAA and L-glutamine on Blood Fatigue Factors and Cytokines in Juvenile Athletes Submitted to Maximal Intensity Rowing Performance. Journal of physical therapy science 2014;26:1241-1246.
 Rennie M. J., MacLennan P. A., Hundal H. S., et al. Skeletal muscle glutamine transport, intramuscular glutamine concentration, and muscle-protein turnover. Metabolism 1989;38:47-51.
 Agostini F, Biolo G. Effect of physical activity on glutamine metabolism. Curr Opin Clin Nutr Metab Care 2010;13:58-64.
 Soeters P. B., Grecu I. Have we enough glutamine and how does it work? A clinician's view. Ann Nutr Metab 2012;60:17-26.
 Biolo G., Zorat F., Antonione R., et al. Muscle glutamine depletion in the intensive care unit. Int J Biochem Cell Biol 2005;37:2169-2179.
 Welbourne T. C. Increased plasma bicarbonate and growth hormone after an oral glutamine load. Am J Clin Nutr 1995;61:1058-1061.
 Biolo G., Iscra F., Bosutti A., et al. Growth hormone decreases muscle glutamine production and stimulates protein synthesis in hypercatabolic patients. Am J Physiol Endocrinol Metab 2000;279:E323-332.
 Nieman D. Exercise Testing & Prescription: McGraw-Hill Education; 2010.
 Kochanska-Dziurowicz A. A., Janikowska G., Bijak A., et al. The effect of maximal physical exercise on relationships between the growth hormone (GH) and insulin growth factor 1 (IGF-1) and transcriptional activity of CYP1A2 in young ice hockey players. J Sports Med Phys Fitness2015;55(3):158-163.
 Voss S. C., Robinson N., Alsayrafi M., et al. The effect of a period of intense exercise on the marker approach to detect growth hormone doping in sports. Drug Test Anal 2014;6:582-586.
 Liu H., Bravata D. M., Olkin I, et al. Systematic review: the effects of growth hormone on athletic performance. Annals of internal medicine 2008;148:747-758.
 Birzniece V., Nelson A. E., Ho K. K. Growth hormone administration: is it safe and effective for athletic performance. Endocrinology and metabolism clinics of North America 2010;39:11-23.
 Ramos S., Gray B., Van Driel M., et al. Recombinant human growth hormone—Effects on cytokine production in healthy young males. Journal of Science and Medicine in Sport 2010;13:e10-e1.
 Bottaro M., Martins B., Gentil P., et al. Effects of rest duration between sets of resistance training on acute hormonal responses in trained women. Journal of Science and Medicine in Sport 2009;12:73-78.
 Traustadottir T., Bosch P. R., Cantu T., et al. Hypothalamic-pituitary-adrenal axis response and recovery from high-intensity exercise in women: effects of aging and fitness. The Journal of clinical endocrinology and metabolism 2004;89:3248-3254.
 Canepari M., Rossi R., Pellegrino M. A., et al. Effects of resistance training on myosin function studied by the in vitro motility assay in young and older men. Journal of applied physiology 2005;98:2390-2395.
 Copeland J. L., Verzosa M. L. Endocrine response to an ultra-marathon in pre- and post-menopausal women. Biol Sport 2014;31:125-131.
 Eliakim A., Brasel J. A., Mohan S, et al. Physical fitness, endurance training, and the growth hormone insulin-like growth factor I system in adolescent females. Journal of Clinical Endocrinology & Metabolism 1996;81:3986-3992.
 Arvat E., Ceda G., Ramunni J., et al. The IGF-I response to very low rhGH doses is preserved in human ageing. Clin Endocrinol 1998;49:757-763.
 Milewicz T., Krzysiek J., Sztefko K., et al. 17beta-estradiol regulation of human growth hormone (hGH), insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) axis in hypoestrogenic, hypergonadotropic women. Endokrynol Pol 2005;56:876-882.
 Eliakim A., Brasel J. A., Mohan S., et al. Increased physical activity and the growth hormone-IGF-I axis in adolescent males. Am J Physiol 1998;275:R308-314.
 Roberts M. D., Dalbo V. J., Sunderland K. L., et al. IGF-1 splice variant and IGF-1 peptide expression patterns in young and old human skeletal muscle prior to and following sequential exercise bouts. Eur J Appl Physiol 2010;110:961-969.
 Kanety H., Karasik A., Klinger B., et al. Long-term treatment of Laron type dwarfs with insulin-like growth factor-1 increases serum insulin-like growth factor-binding protein-3 in the absence of growth hormone activity. Acta endocrinologica 1993;128:144-149.
 Rosa C., Vilaca-Alves J., Fernandes H. M., et al. Order effects of combined strength and endurance training on testosterone, cortisol, growth hormone and IGFBP-3 in concurrent-trained men. J Strength Cond Res 2015;29(1):74-79.