Use short rest periods between training set to build muscle and lose fat. Manipulating the hormone response to exercise is one of your best tools to get fast body composition results, and two recent studies show how you can program rest periods along with load, volume, and tempo to do this.
The first study found that using short 27-second rest periods for 12 sets of 3 reps of the squat produced greater blood lactate buildup than two other protocols that used longer 60-second rest periods. Researchers suggest that the shortest rest condition was metabolically more taxing and will thereby result in more growth hormone being released, which will lead to greater fat burning in the body.
The longer rest conditions allowed the subjects to produce the most power—a good strategy to use if your goal is sports performance. Take away that all of these programming schemes can be used in your training, since there’s value for body composition in training high speed movements with maximal force because you train the central nervous system. But, you’ll always want to come back to short rest intervals that stress the body, and the second recent study provides more support for doing so.
Two traditional training protocols compared the effect of 60- or 90-second rest intervals on testosterone and cortisol response in trained young men. The loading/rest schemes were as follows: a hypertrophy protocol at 70 percent of the 1RM with 3 sets of 10 reps, and a strength protocol at 85 percent of the 1RM with 8 sets of 3 reps. Both protocols trained the barbell bench press, back squat, lat pull-down, and knee extension.
Results showed that the 60-second rest interval using the hypertrophy protocol produced a 22.5 percent increase in testosterone response post-workout, which was the greatest increase of all trials. The hypertrophy protocol using 90-second rest intervals produced the second greatest testosterone response, with an elevation of 20 percent. Still significant, both rest intervals of 60 and 90 seconds using the strength protocol increased testosterone by about 13 percent. None of the protocols increased cortisol, indicating they can be used to build muscle and strength without causing too much catabolic stress.
This evidence comes after a few recent studies suggesting that hormone response to training is very individualized—especially testosterone response. This may be due to variations in diet, nutrient timing, or the use of an inadequate volume load. Regardless, there is enough support for programming your carefully manipulating your rest intervals to overload the body and for maximal muscle gains and fat loss.
Villanueva, M., Villanueva, M., et al. Acute Hormonal Responses to Various Resistance Training Schemes. Journal of Strength and Conditioning Research. 2012. Published Ahead of Print.
Paulo, C., Roschel, H., et al. Influence of Different Resistance Exercise Loading Schemes on Mechanical Power Output in work to rest Ratio—Equated and Nonequated Conditions. Journal of Strength and Conditioning Research. 2012. 26(5), 1308-1312.