Less Rest Between Sets Equals More Muscle | Science Proves It
Less Rest Between Sets Equals More Muscle
A key factor influencing training intensity and subsequent muscle growth is the amount of rest taken between sets. When training for strength, the recommended rest interval typically lasts between two to five minutes. This length of time provides the recovery necessary to maintain the desired repetition range throughout the workout for the most positive influence on strength. Alternatively, decreasing the rest interval to around 30 to 60 seconds does not allow for complete recuperation, putting considerable stress on the muscle that preferentially drives muscle growth.
Although the suggested length of the rest interval appears to be well established, studies show that frequent training with short rest intervals and relatively heavy weights results in adaptations within the body that can preserve training intensity, or repetition range, throughout the workout, even while using short rest periods. In theory, the capacity to simultaneously lift heavier weights with shorter rest periods should result in excellent gains in both size and strength. Furthermore, research also indicates that supplementing this training scheme with certain ergogenic aids that speed up muscle recuperation, such as creatine monohydrate, will promote even greater levels of concurrent muscle growth and strength gains.
Muscular Adaptations to Shorter Rest Periods
The capacity of the human body to adapt to resistance exercise is a well-known phenomenon with clear-cut rules that at times appear immutable. In the world of exercise science, one deep-rooted principle that is typically unquestioned is the optimal length of rest required between sets for different outcomes, such as muscle growth or muscle strength, with strength gains typically requiring relatively longer rest intervals.
Despite these apparent certainties, a study by Kraemer et al. suggests these rules should be challenged— as it was found that specific training practices can reduce the amount of rest needed between sets, even while training with moderately heavy weights. In this study, a group of male bodybuilders and powerlifters performed circuit training for the entire body that involved 10 different exercises. Each exercise included three consecutive sets using a weight that allowed 10 repetitions in each set. Subjects rested 10 seconds between sets, and about 60 seconds in between each exercise.
The crucial finding of this study was that the bodybuilders were much better at sustaining the desired repetition range throughout the entire workout, conceivably because this training approach was performed with weights and rest intervals typically used by competitive bodybuilders. Consequently, the bodybuilders were able to resist the effects of muscle fatigue because of adaptations caused by their training style.
The authors of this study concluded that some of the key training adaptations that improved muscular performance in the bodybuilding group included increased mitochondrial density within the muscle, which would enhance the muscle cell’s energy production, thus resisting muscular fatigue. Additionally, the researchers theorized that an enhanced buffering capacity within the muscles of the bodybuilding group would mitigate the negative influence that lactic acid has on muscular contraction, ultimately improving exercise performance.
Altogether, the results of the above study highlight the remarkable ability of the body to adapt to different exercise stimuli, which in this case specifically, provides the ability to sustain training intensity, even while using short rest periods.
Shorter Rest Intervals Concurrently Enhance Size and Strength
The adaptation of the body to short rest intervals demonstrated in the aforementioned study by Kraemer et al. suggests that shorter rest intervals with high-intensity training should increase both muscle size and strength simultaneously. In order to see whether this training approach could achieve size and strength, a study by Villaneuva et al. investigated a workout approach mixing high-intensity training with short rest intervals. In this study, researchers exposed two groups to high-intensity resistance training, while allowing short rest periods of 60 seconds for one group and 90 seconds for the second group. The results show that both groups increased testosterone levels, which boosts muscle mass, while also exhibiting considerable strength gains.
Combine Creatine With Shorter Rest Intervals for Superior Gains in Size and Strength
Creatine monohydrate supplementation combined with resistance training has been shown to synergistically accentuate muscle hypertrophy and strength. The positive effects from creatine monohydrate on muscle tissue occur, in part, because creatine is converted in the body into creatine phosphate, which functions by replenishing energy in the form of ATP within the muscle cell. The increased energy within the muscle cell extends the duration of muscular contraction, effectively resisting muscle fatigue, which ultimately improves muscle growth and strength.
Seeing that the rest interval also lessens muscle fatigue with longer rest periods normally required for optimal strength training, perhaps the use of creatine monohydrate could decrease the requirement, to some degree, for longer rest intervals between sets when lifting heavier weights. Creatine monohydrate could effectively permit shorter rest periods that promote sufficient rest to support strength gains, while also providing the anabolic stimulus normally triggered by short rest periods.
To see if creatine monohydrate could reduce the absolute requirement for longer rest periods while using fairly heavy weight, a study by Souza-Junior et al.1 compared strength and hypertrophy responses to resistance training programs that used either longer rest intervals of two minutes, or shorter rest intervals that decreased during the eight-week study, from 105 seconds to 30 seconds. All subjects did the same exercises while performing eight to 10 reps for all sets. In addition, all subjects supplemented with identical amounts of creatine monohydrate throughout the study.
The results of the study showed that the combination of creatine monohydrate supplementation with resistance training increased muscular size and strength to a similar degree, despite the rest interval length between sets. The authors of the study concluded that because the volume of training was significantly greater for the group using a two-minute rest interval compared to the group that had shorter rest intervals, but strength gains were similar in both groups, that creatine supplementation apparently improved strength more effectively for the short rest interval group. These results suggest that creatine monohydrate can reduce the requirement for longer rest intervals when training with heavier weights for strength gains.
Clearly, the above study would have been more conclusive if it included a third group that consumed creatine, used short rest intervals and performed a training volume similar to the group utilizing two-minute rest intervals, to see if they gained the most size and strength. Nevertheless, despite the shortcomings of this study, the data support the hypothesis that creatine monohydrate improves the recuperative capacity of muscle tissue, reducing the requirement for more extensive periods of rest between sets— particularly during high-intensity training, which normally requires longer periods of rest for optimal muscular performance.
For most of Michael Rudolph’s career he has been engrossed in the exercise world as either an athlete (he played college football at Hofstra University), personal trainer or as a research scientist (he earned a B.Sc. in Exercise Science at Hofstra University and a Ph.D. in Biochemistry and Molecular Biology from Stony Brook University). After earning his Ph.D., Michael investigated the molecular biology of exercise as a fellow at Harvard Medical School and Columbia University for over eight years. That research contributed seminally to understanding the function of the incredibly important cellular energy sensor AMPK— leading to numerous publications in peer-reviewed journals including the journal Nature. Michael is currently a scientist working at the New York Structural Biology Center doing contract work for the Department of Defense on a project involving national security.