Will Training Arms Twice a Week Increase Muscle Growth?
There is much debate on the strength training variables most responsible for improvements in lean mass and strength. Some bodybuilders such as Ronnie Coleman and Jay Cutler trained each body part twice per week, whereas other top ranked bodybuilders train each body part once per week. The research has been inconclusive, with some studies finding training each body part more frequently resulted in greater muscle mass than training each body part once per week. In a previous review of the literature on training frequency concerning muscle hypertrophy and training frequency, the researchers showed there was no difference in muscle size gains between frequencies of two and three days per week; they also concluded that muscle size gains can be made with training frequencies of anywhere between two and four times per week for as long as six months. So in sum, training a body part more often is not going to make it grow as opposed to training it one time per week. What about gains in strength?
Does Greater Training Frequency Increase Muscle Strength?
Researchers wanted to assess the effects of 1 hour of resistance training on muscular strength and health outcomes when allocated differently over the course of a week. The subjects performed with the same total training volume but with different training frequencies and durations, or with varying levels of supervision, on compliance, muscle health and performance, behavior and work performance. The subjects performed shoulder exercises consisting of the front raise, lateral raise, reverse flyes, shrugs, and wrist extension. The loading for these exercises ranged from 8 – 20 RM.
Researchers allocated subjects into five different groups:
-1 session x 60 minutes (supervised)
-3 sessions per week x 20 minutes (supervised)
-3 sessions per week x 20 minutes (unsupervised),
-9 sessions per week x 7 minutes (unsupervised)
-a non-training control.
So all the subjects performed the same volume except that the training frequency varied among the groups. The researchers found that the four training groups significantly increased 1RM strength, but there was no similar increase in the control group. Increases in the 1 x 60 minute, 3 x 20 minutes (supervised), 3 x 20 minute (unsupervised) and 9 x 7 minute groups were: 12.7%, 6.0%, 8.8%, and 4.4%, respectively. However, there were no significant differences between groups. The researchers concluded that resistance training programs comprised of equal volume but different training frequency displayed similar results concerning gains in muscular strength.
The interesting finding of the study was that regardless of how many times a person went to the gym, either 1 or 3 times per week, when the volume of a protocol is achieved, it did not matter how long the person exercises, as all the groups made similar gains in strength, but the key was to maintain a consistent volume during exercise.
Researchers examined the effect strength training frequency has on improvements in lean mass and strength. Participants were assigned to one of two groups. The researchers kept the training volume the same for both groups, so both groups did the same training but the workout frequency was more often for one group.
–High-frequency training group trained each muscle group as the agonist, three times per week, exercising with three sets per muscle group per session (3 total body workouts). High-frequency training group trained each muscle group three times per week, by training the whole body on three different days. High-Frequency Training (three sets on three occasions per week)
–Low-frequency training group trained each muscle group as the agonist one time per week, completing all nine sets during that one workout. Low-frequency training consisted of a routine split over three days: 1) pectorals, deltoids, and triceps; 2) upper back and biceps; 3) quadriceps, hamstrings, calves, and abdominals. Low-Frequency Training (nine sets, on one occasion per week).
Repetitions per set were 8-12, equaling a load intensity of ~75-85% of the participant’s 1-repetition maximal repetition. Daily workouts lasted ~45-60 minutes, and the total training period was eight weeks. Participants were supervised throughout the eight weeks of training.
At the end of eight weeks, both high-frequency and low-frequency workouts produced similar improvements in strength and lean mass. Lean mass improvements for the current study resulted in almost identical increases with 1.9% for high-frequency and 2.0% for low frequency. The study found that chest press strength improvements of 11% for high-frequency and 7% for low-frequency. Hack squat strength improved 21% for high-frequency workouts and 24% for low-frequency, but these were not statistically different, meaning that they were similar.
The research suggests that when training volume is kept similar, it does not prove advantageous to train a body part more than once a week. There does not seem to be any differences in strength, or lean muscle mass increases when training volume is kept the same.
Increasing lean mass and strength – a comparison of high-frequency strength training to low frequency strength training, by Thomas & Burns, in International Journal of Exercise Science (2016) Dalager T, Bredahl TG, Pedersen MT, Boyle E, Andersen LL, Sjøgaard G. Does training frequency and supervision affect compliance, performance, and muscular health? A cluster randomized controlled trial. Man Ther. 2015 Feb 28. Wernbon M, Augustsson J and Thomee R. The influence of frequency, intensity, volume and mode of strength training on a muscle cross-sectional area in humans. Sports Medicine, 37:225-264, 2007.