The Effects of Resistance Exercise Selection on Muscle Size and Strength in Trained Women

The study compared the effects of resistance training programs composed by multi-joint (MJ), single-joint (SJ) and the combination of multi- and single-joint (MJ+SJ) exercises on muscle strength and hypertrophy in trained women. Thirty participants were divided into groups that performed only MJ exercises, SJ exercises and MJ+SJ exercises for six months. Participants were tested for 1-repetition maximum (RM) and muscle thickness (MT) before and after the intervention. All groups showed significant gains on 1RM tests from pre- to post-training (P<0.01). However, MJ and MJ+SJ groups obtained greater gains in 1RM for the MJ exercises in comparison with the SJ group. Increases in 1RM for the SJ exercises were similar among groups, with the exception of leg curl, where the SJ group obtained greater gains than MJ and MJ+SJ. All groups obtained significant increases in MT from pre- to post-training for all muscle groups. However, MJ and MJ+SJ groups presented greater increases in gluteus maximus, quadriceps femoris and pectoralis major in comparison with the SJ group. Therefore, our results suggest that, in general, performing MJ exercises seems to be necessary to obtain optimal results from a resistance training program; however SJ might be necessary to provide optimal strength gains in knee flexion.