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by:  Robbie Durand, M.A., C.S.C.S.
“I have always trained the same, higher volume, short rest periods; it keeps it challenging which I thrive on.” – Jay Cutler

And now the classic question: how much rest should a bodybuilder take between sets? It all depends on your training goals. If you are looking to get stronger, the best rest periods should be 3 to 5 minutes between sets. The Discovery Channel once did a documentary on the 2000 Olympic Gold Medal Olympic weightlifter Winner Naim Suleymanoglu from Bulgaria otherwise known as “Pocket Hercules.” He became the second lifter (of only seven) to clean and jerk three times his bodyweight in history. Amazingly, he smokes about 50 cigarettes a day and sometimes between sets he would catch a quick smoke during those 5 minute rest periods!

This is relatively unheard of in the bodybuilding world, where mass training is best achieved through multiple sets and relatively short rest periods between them—1 minute or so. Often when competition dates approach and bodybuilders want to get leaner you will see them taking even shorter rest periods between sets. Bodybuilders somehow intuitively know that increasing exercise intensity by reducing rest periods does something to increase fat metabolism. Yet, for a long time there was little to no research as to how this was being accomplished. It’s as if this was mysteriously passed down from generation to generation of bodybuilders without any real science to back it up. Three-time Mr. Olympia Frank Zane had unbelievable definition for a bodybuilder in the 1970’s. When asked how he achieved his definition he said,

That comes from experience. When you really get into your workout, the last month before a contest, the concentration is so keen (no talking, and almost no rest) going through maximum effort each set. It’s sort of like everything disappears except what you are into at the time.

Higher Intensity Exercise Results in Greater Fat Loss

So to recap Bodybuilders have always known that increasing exercise intensity increases fat burning but the mechanism was not really clear. Perhaps the most compelling evidence on the effects of high-intensity exercise came in 1994 in the now infamous journal of Metabolism. This study tracked two groups of people undergoing different modes of exercise. Group 1 did zone aerobic training for a period of 20 weeks, while Group 2 performed 15 weeks of a high-intensity interval program. The researchers wanted to see how each program would affect body fatness and metabolism. The results showed that the aerobic group burned 48% more calories than the interval group over the course of the study. However, despite the huge caloric disadvantage, the interval group had a nine fold greater loss in subcutaneous fat. Additionally, resting levels of 3-hydroxyacyl coenzyme A dehydrogenase (HADH), an enzymatic marker of fat-burning, were significantly elevated in the interval group (11). Many bodybuilders often perform aerobic exercise before a show. But would interval training be better for fat loss? It has been shown that interval training causes a rise in lipolysis during the post-exercise period (5). As demonstrated in the above study, something was definitely going on in the interval training group that was causing them to burn more fat. The trigger for this post exercise increase in metabolic rate and fat loss seems to point toward GH.

GH Increases are Dependent on Training Intensity

The most powerful, non pharmacological stimuli for GH secretion are sleep and exercise. Exercise is a powerful stimulator of GH secretion, and the size of the increase in exercise GH is related to the exercise intensity (1). A single 30-s treadmill sprint to exercise failure produces a near-maximal GH response with GH levels remaining elevated for at least 60 min postexercise (2). As serum GH was still approximately ten times higher than baseline after 1 h of recovery after maximal sprint exercises, it is suggested that the exercise-induced increase in GH could have important physiological effects in building mass, including increased protein synthesis and sparing of protein breakdown leading to increased muscle mass. Although this study looked at sprints to maximal failure, studies which have utilized squats and deadlifts to failure have elicited similar GH responses. Clearly, as training intensity increases so does GH secretion! In a recent study published in the European Journal of Applied Physiology, Bill Kraemer a world renowned exercise endocrinologist wrote, “The importance of greater GH response to exercise cannot be understated in terms of muscle signaling pathways. GH plays an important role in protein synthesis via interactions with the GH receptor on the cell membrane and subsequently increases in translation efficiency.” (20) GH’s anabolic actions cannot be emphasized enough with regard to increased protein synthesis.

Take Your Amino Acids before Exercise

There is debate as whether one should take amino acids (BCAA’s) before or after exercise. Some studies have shown its better to take BCAAs before while others have determined it does not matter when. Here is my rationale as to why it may be more important to take them before exercise. In a recent paper written by protein synthesis gurus Arny Ferranado and Robert Wolfe, the authors mentioned an interesting study involving GH and protein synthesis. Subjects were randomly assigned to receive daily subcutaneous injections of placebo (saline) or GH. Each subject was studied in the fasted state, followed by an infusion of the same commercial amino acid formula. The results clearly demonstrated no difference in fasted net protein balance between the placebo and GH groups. The principal effect of GH was realized when combined with amino acids, as there was a clear anabolic effect (22). Based on the study, GH is most effective in the presence of amino acids. Back in 1998, Dr. Kraemer did an interesting study where he looked at post-exercise GH responses in response to weight trainers that took a protein based supplement before exercise for three consecutive days and compared them to those that ingested just water. Serum GH concentrations significantly increased immediately post exercise and returned to resting concentrations by 60 min of recovery in both groups. On day 1, GH concentrations at 0, 15, and 30 min post exercise were significantly higher in the group consuming the protein supplement compared to placebo (33). Finally, several amino acids have been shown to increase serum GH concentrations, including the BCAA leucine. It makes sense to take amino acids just before the GH peak that occurs with intense exercise. This facilitates the greatest anabolic effect compared to post exercise BCAA consumption when GH levels are already in decline. That about does it for our Part I of this look at Growth Hormone and body composition. In Part II, we’ll look at GH’s effects on abdominal adipose tissue, more on its post-exercise metabolic impact, Catecholamines and more.


1. Pritzlaff CJ, Wideman L, Weltman JY, Abbott RD, Gutgesell ME, Hartman ML, Veldhuis JD, Weltman A. Impact of acute exercise intensity on pulsatile growth hormone release in men. J Appl Physiol. 1999 Aug;87(2):498-504. 2. Nevill ME, Holmyard DJ, Hall GM, Allsop P, van Oosterhout A, Burrin JM, Nevill AM. Growth hormone responses to treadmill sprinting in sprint- and endurance-trained athletes. Eur J Appl Physiol Occup Physiol. 1996;72(5-6):460-7. 3. Moller N, Gjedsted J, Gormsen L, Fuglsang J, Djurhuus C. Effects of growth hormone on lipid metabolism in humans. Growth Horm IGF Res. 2003 Aug;13 Suppl A:S18-21. Review. 4. Enevoldsen LH, Polak J, Simonsen L, Hammer T, Macdonald I, Crampes F, de Glisezinski I, Stich V, Bulow J. Post-exercise abdominal, subcutaneous adipose tissue lipolysis in fasting subjects is inhibited by infusion of the somatostatin analogue octreotide. Clin Physiol Funct Imaging. 2007 Sep;27(5):320-6. 5. N.A. Mulla, L. Simonsen, J. Bulow, Post-exercise adipose tissue and skeletal muscle lipid metabolism in humans: the effects of exercise intensity, J. Physiol. 524 (2000) 919–928. 6. Wee J, Charlton C, Simpson H, Jackson NC, Shojaee-Moradie F, Stolinski M, Pentecost C, Umpleby AM. GH secretion in acute exercise may result in post-exercise lipolysis. Growth Horm IGF Res. 2005 Dec;15(6):397-404. 7. Berlan M, Lafontan M. The alpha 2-adrenergic receptor of human fat cells: comparative study of alpha 2-adrenergic radioligand binding and biological response. J Physiol. 1982; 78:279–87. 8. Mauriege P, Galitzky J, Berlan M, Lafontan M. Heterogeneous distribution of beta and alpha-2 adrenoceptor binding sites in human fat cells from various fat deposits: functional consequences. Eur J Clin Invest. 1987;17:156–65. 9. Rosenthal, M. J., andW. F.Woodside. Nocturnal regulation of free fatty acids in healthy young and elderly men. Metabolism 37: 645–648, 1988. 10. Gravholt CH, Schmitz O, Simonsen L, Bulow J, Christiansen JS, Moller N. Effects of a physiological GH pulse on interstitial glycerol in abdominal and femoral adipose tissue. Am J Physiol. 1999 Nov;277(5 Pt 1):E848-54. 11. Tremblay A, Simoneau JA, Bouchard C. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism. 1994 Jul;43(7):814-8. 12. Laursen T, Jørgensen JOL, Christiansen JS 1994 Metabolic effects of growth hormone administered subcutaneously once or twice daily to growth hormone deficient adults. Clin Endocrinol 41:337-343. 13. Wolfe RR, Klein S, Carraro F, Weber JM 1990 Role of triglyceride-fatty acid cycle in controlling fat metabolism in humans during and after exercise. Am J Physiol 258:E382-9. 14. Gibney J, Healy ML, Stolinski M, et al. 2003 Effect of growth hormone (GH) on glycerol and free fatty acid metabolism during exhaustive exercise in GHdeficient adults. J Clin Endocrinol Metab 88:1792-7. 15. Kanaley JA, Dall R, Moller N, et al. 2004 Acute exposure to GH during exercise stimulates the turnover of free fatty acids in GH-deficient men. J Appl Physiol 96:747-53. 16. Pritzlaff CJ, Wideman L, Blumer J, et al. 2000 Catecholamine release, growth hormone secretion, and energy expenditure during exercise vs. recovery in men. J Appl Physiol 89:937-46. 17. Marcus C, Bolme P, Micha-Johansson G, Margery V, Bronnegard M 1994 Growth hormone increases the lipolytic sensitivity for catecholamines in adipocytes from healthy adults. Life Sci 54:1335-41 18. Beauville M, Harant I, Crampes F, et al. 1992 Effect of long-term rhGH administration in GH-deficient adults on fat cell epinephrine response. Am J Physiol 263:E467-72. 19. Harant I, Beauville M, Crampes F, et al. 1994 Response of fat cells to growth hormone (GH): effect of long term treatment with recombinant human GH in GH deficient adults. J Clin Endocrinol Metab 78:1392-5. 20. Kraemer WJ, Hatfield DL, Spiering BA, Vingren JL, Fragala MS, Ho JY, Volek JS, Anderson JM, Maresh CM. Effects of a multi-nutrient supplement on exercise performance and hormonal responses to resistance exercise. Eur J Appl Physiol. 2007 Nov;101(5):637-46. 21. Poehlman ET, Melby C. Resistance training and energy balance. Int J Sport Nutr. 1998 Jun;8(2):143-59. Review. 22. Ferrando AA, Wolfe RR. Restoration of hormonal action and muscle protein. Crit Care Med. 2007 Sep;35(9 Suppl):S630-4. 23. Reeves GV, Kraemer RR, Hollander DB, Clavier J, Thomas C, Francois M, Castracane VD. Comparison of hormone responses following light resistance exercise with partial vascular occlusion and moderately difficult resistance exercise without occlusion. J Appl Physiol. 2006 Dec;101(6):1616-22. 24. M.S. Vigas, S. Nemeth, L. Jurcoricora, J. Mikula, L. Komadel, The importance of lactate in exercise-induced growth hormone release in man. Radioimmunoassays: methodology and applications in physiology and clinical studies, Horm. Metab. Res. 5 (Suppl) (1974) 166–169. 25. J.R. Sutton, N.L. Jones, C.J. Toews, Growth hormone secretion and acid–base alteration at rest and during exercise, Clin. Sci. Mol. Med. 50 (1976) 241–247. 26. Holt RI, Webb E, Pentecost C, Sonksen PH. Aging and physical fitness are more important than obesity in determining exercise-induced generation of GH. J Clin Endocrinol Metab. 2001 Dec;86(12):5715-20. 27. Vettor R, Macor C, Rossi E, Piemonte G, Federspil G. Impaired counterregulatory hormonal and metabolic response to exhaustive exercise in obese subjects. Acta Diabetol. 1997 Aug;34(2):61-6. 28. Wong T, Harber V. Lower excess postexercise oxygen consumption and altered growth hormone and cortisol responses to exercise in obese men. J Clin Endocrinol Metab. 2006 Feb;91(2):678-86. Epub 2005. 29. Watt, PW, Finley, E, Cork, S, Legg, RA, Vernon, RG. (1991) Chronic control of the ß- and 2-adrenergic systems of sheep adipose tissue by growth hormone and insulin Biochem J 273,39-42 30. Yang, S, Xu, X, Björntorp, P, Edén, S. (1995) Additive effects of growth hormone and testosterone on lipolysis in adipocytes of hypophysectomized rats J Endocrinol 147,147-152. 31. Ricketts ML, Verhaeg JM, Bujalska I, Howie AJ, Rainey WE, Stewart PM 1998 Immunohistochemical localization of type 1 11ß-hydroxysteroid dehydrogenase in human tissues. J Clin Endocrinol Metab 83:1325–1335. 32. Tomlinson JW, Crabtree N, Clark PM, Holder G, Toogood AA, Shackleton CH, Stewart PM. Low-dose growth hormone inhibits 11 beta-hydroxysteroid dehydrogenase type 1 but has no effect upon fat mass in patients with simple obesity. J Clin Endocrinol Metab. 2003 May;88(5):2113-8. 33. Kraemer WJ, Volek JS, Bush JA, Putukian M, Sebastianelli WJ. Hormonal responses to consecutive days of heavy-resistance exercise with or without nutritional supplementation. J Appl Physiol. 1998 Oct;85(4):1544-55.


No Increases in Post-Exercise Fat Utilization without Acute Increases in GH – Part I