“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,

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.