Sooneste, H, Tanimoto, M, kakigi, R, Saga, N, Katamoto, S. 2013. "Effects of Training Volume on Strength and Hypertrophy in Young Men". Journal of Strength and Conditioning Research. Volume 27 Issue 1. 8-13.
It is known that resistance training is the primary method of increasing strength and muscle size, but the limited research offers little clinical evidence to prove what training parameters are more effective and efficient and which are not.
Research on hypertrophy rates and exercise training volume in youth is fairly limited. Researchers at Juntendo University in Japan completed a study on young men and hypertrophy in the upper body, comparing the effects of lower versus higher training volume. Volume is a measure of the total amount of work done, or the total number of repetitions. 1 set of 10 would be a total volume of 10, whereas 5 sets of 10 would be a total volume of 50.
In this study, 8 men averaging 25 years of age and weighing approximately 64kg were given a program which randomly assigned each arm one of two training programs. This helped to isolate the variable of genetics and body type. The subjects were all untrained individuals. At baseline and at the end of the 12 week study, strength and cross-sectional area of the upper arm were measured.
The subjects trained their elbow flexor muscles (biceps bracchi, brachialis and brachioradialis) twice per week, doing a seated preacher dumbbell curl. The low volume arm performed just 1 set of repetitions while the high volume set performed 3 sets, all were performed at 80% of the 1 repetition maximum.
At 12 weeks, it was found that the cross-sectional area of the upper arm increased by about 13% for the 3-set protocol, while the 1-set protocol caused an increase of approximately 8%. For strength, the 3-set protocol tended to increase strength more on average, compared to the single set, at 32% versus 20%.
This study exemplifies the difference that volume can make on training, particularly in untrained individuals. It should be noted that the training intensity, set to 80% of 1RM, was a baseline, and may also have an effect on both strength and hypertrophy. The authors of the study state that the results are to be interpreted within the context of study only, and that this population should be training more days per week at a light volume of 1 set to maintain consistency and prevent over-training.