Bodybuilders and other strength athletes who rest for 1 minute between sets build more muscle mass, strength and speed than athletes who rest for 4 minutes. Sports scientists at the University of Southern California discovered this when they did an experiment with 22 men in their sixties.
As the population greys, the number of elderly people whose functioning decreases as a result of muscle decay is on the increase. The best medicine against this is strength training, but scientists are still not sure what kind of strength training is optimal. In this study, which will soon be published in the European Journal of Applied Physiology, the researchers looked at the effect of the length of the rest between sets on the muscles.
Short rest between strength-training sets results in more muscle
The researchers got their subjects to do four weeks of strength training first so that they became accustomed to this form of exercise. Then they divided the men into two groups.
All 22 men trained three times a week, and during each workout they trained all big muscle groups in the body, doing 4-6 basic exercises including leg-presses, bench-presses, dumbbell-stepups, Romanian deadlifts, lat-rows and lat-pulldowns. All of the men did 2-3 sets of 4-6 reps for each exercise.
One group rested for 1 minute between sets, the other for 4 minutes.
In the eight weeks that the experiment lasted the men who rested for 1 minute between sets built up more muscle mass than the men in the other group.
The men who took 1-minute pauses also built up more strength. Solid line: 1-minute rest; broken line: 4-minute rest.
When the researchers got the men to climb stairs – to be precise they got their subjects to do the Margaria Stair-Climbing Test – they discovered that the men who had trained with shorter rests were faster than the men who had rested for 4 minutes between sets.
“The results of the current investigation offer a novel strategy for prescribing strength resistance training in a population of healthy older men, as well as a model for periodization that may potentially optimize both hypertrophic and neural adaptations to long-term periodized resistance training”, the researchers write.”
“Prescribing strength resistance exercise and periodized strength resistance training for older men with relatively short rest interval lengths in between sets may optimize hypertrophic and performance adaptations to short-term strength resistance training and, therefore, maximally offset the age-related declines in lean body mass, strength, and power.”
Short rest interval lengths between sets optimally enhance body composition and performance with 8 weeks of strength resistance training in older men.
To determine if 8 weeks of periodized strength resistance training (RT) utilizing relatively short rest interval lengths (RI) in between sets (SS) would induce greater improvements in body composition and muscular performance, compared to the same RT program utilizing extended RI (SL).
22 male volunteers (SS: n = 11, 65.6 ± 3.4 years; SL: n = 11, 70.3 ± 4.9 years) were assigned to one of two strength RT groups, following 4 weeks of periodized hypertrophic RT (PHRT): strength RT with 60-s RI (SS) or strength RT with 4-min RI (SL). Prior to randomization, all 22 study participants trained 3 days/week, for 4 weeks, targeting hypertrophy; from week 4 to week 12, SS and SL followed the same periodized strength RT program for 8 weeks, with RI the only difference in their RT prescription.
Following PHRT, all study participants experienced increases in lean body mass (LBM) (p < 0.01), upper and lower body strength (p < 0.001), and dynamic power (p < 0.001), as well as decreases in percentage body fat (p < 0.05). Across the 8-week strength RT phase, SS experienced significantly greater increases in LBM (p = 0.001), flat machine bench press 1-RM (p < 0.001), bilateral leg press 1-RM (p < 0.001), narrow/neutral grip lat pulldown (p < 0.01), and Margaria stair-climbing power (p < 0.001), compared to SL.
This study suggests 8 weeks of periodized high-intensity strength RT with shortened RI induces significantly greater enhancements in body composition, muscular performance, and functional performance, compared to the same RT prescription with extended RI, in older men. Applied professionals may optimize certain RT-induced adaptations, by incorporating shortened RI.
PMID: 25294666 [PubMed - as supplied by publisher]