A study published this month in the Journal of Strength and Conditioning Research looked at the effect of supervised workouts on building lean muscle mass in a health club setting. The researchers hypothesized that “club members randomized to receive an evidence-based training program would accrue greater improvements in lean body mass (LBM) and other fitness measures than members randomized to self-training”. The subjects were all men between the ages of 30-44 years old who were members of a club in Southern California. Both groups (n=17) trained 3x/week for 12-weeks.
The trained group saw a significant increase in LBM of 1.3 kg (2.86 pounds) following 12-weeks of training while the self-trained group saw no change at all. The trained group also saw a 2 percent decrease in body fat while the self-trained saw only a 1 percent change. The trained group also experienced an increase in 1-RM in chest press (42%) and leg press (35%) while the self-trained saw increases of 19 and 23 percent respectively. In terms of aerobic capacity (VO2 max), there was a 7 percent increase in maximal oxygen uptake for the trained group and 3 percent decrease for the self-trained group. Dietary intake was not controlled for in this study.
Storer TW, Dolezal BA et al., (2014). Effect of Supervised, Periodized Exercise Training vs. Self-Directed Training on Lean Body Mass and Other Fitness Variables in Health Club Members, J. Strength and Conditioning Research, 28(7):1995-2006.