Abstract: Storer, TW, Dolezal, BA, Berenc, MN, Timmins, JE, and Cooper, CB. Effect of supervised, periodized exercise training vs. self-directed training on lean body mass and other fitness variables in health club members. J Strength Cond Res 28(7): 1995–2006, 2014—Conventional wisdom suggests that exercise training with a personal trainer (PTr) is more beneficial for improving health-related fitness than training alone. However, there are no published data that confirm whether fitness club members who exercise with a PTr in the fitness club setting obtain superior results compared with self-directed training. We 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. Men, aged 30–44 years, who were members of a single Southern California fitness club were randomized to exercise with a PTr administering a nonlinear periodized training program (TRAINED, N = 17) or to self-directed training (SELF, N = 17); both groups trained 3 days per week for 12 weeks. Lean body mass was determined by dual-energy x-ray absorptiometry. Secondary outcomes included muscle strength 1 repetition maximum (1RM), leg power (vertical jump), and aerobic capacity (V[Combining Dot Above]O2max). TRAINED individuals increased LBM by 1.3 (0.4) kg, mean (SEM) vs. no change in SELF, p = 0.029. Similarly, significantly greater improvements were seen for TRAINED vs. SELF in chest press strength (42 vs. 19%; p = 0.003), peak leg power (6 vs. 0.6%; p < 0.0001), and V[Combining Dot Above]O2max (7 vs. −0.3%; p = 0.01). Leg press strength improved 38 and 25% in TRAINED and SELF, respectively (p = 0.14). We have demonstrated for the first time in a fitness club setting that members whose training is directed by well-qualified PTrs administering evidence-based training regimens achieve significantly greater improvements in LBM and other dimensions of fitness than members who direct their own training.
1Division of Pulmonary Medicine, Exercise Physiology Research Laboratory, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California;
2Equinox Fitness Clubs, Los Angeles, California; and
3Division of Endocrinology, Diabetes & Hypertension, Gonda (Goldschmied) Diabetes Center, University of California at Los Angeles, Los Angeles, California
Address correspondence to Thomas W. Storer, firstname.lastname@example.org.