Influence of exercise training on physiological and performance changes with weight loss in men. Med. Sci. Sports Exerc., Vol. 31, No. 9, pp. 1320-1329, 1999.
The purpose of this study was to examine the physiological effects of a weight-loss dietary regimen with or without exercise.
Thirty-five overweight men were matched and randomly placed into either a control group (C; N = 6) or one of three dietary groups; a diet-only group (D; N = 8), a diet group that performed aerobic exercise three times per week (DE; N = 11); and a diet group that performed both aerobic and strength training three times per week (DES; N = 10).
After 12 wk, D, DE, and DES demonstrated a similar and significant (P ≤ 0.05) reduction in body mass (−9.64, −8.99, and −9.90 kg, respectively) with fat mass comprising 69, 78, and 97% of the total loss in body mass, respectively. The diet-only group also demonstrated a significant reduction in fat-free mass. Maximum strength, as determined by 1-RM testing in the bench press and squat exercise was significantly increased for DES in both the bench press (+19.6%) and squat exercise (+32.6%). Absolute peak O2 consumption was significantly elevated in DE (+24.8%) and DES (+15.4%). There were no differences in performance during a 30-s Wingate test for the DE and DES, whereas D demonstrated a significant decline in peak and mean power output. Resting metabolic rate (RMR) (kcal·d−1) was not significantly different for any of the groups except for the DE group. There were no significant changes in basal concentrations of serum glucose, BUN, cortisol, testosterone, and high density lipoprotein (HDL) cholesterol for any of the groups. Serum total cholesterol and low density lipoprotein (LDL) cholesterol were significantly decreased for all dietary groups. Serum triglycerides were significantly reduced for D and DES at week 6 and remained lower at week 12 for D, while triglycerides returned to baseline values for DES.
These data indicate that a weight-loss dietary regimen in conjunction with aerobic and resistance exercise prevents the normal decline in fat-free mass and muscular power and augments body composition, maximal strength, and maximum oxygen consumption compared with weight-loss induced by diet alone.
Department of Kinesiology, Noll Physiological Research Center, and Center for Sports Medicine, The Pennsylvania State University, University Park, PA, 16802; and The Human Performance Laboratory, Ball State University, Muncie, IN 47306
Submitted for publication January 1998.
Accepted for publication June 1998.
This study was supported in part by a grant from Matol Botanical International LTD (Montreal, Canada). Additional support was from the Robert F. and Sandra M. Leitzinger Research Fund in Sports Medicine at the Pennsylvania State University. We would like to thank a dedicated group of subjects who made this project possible. Also, special thanks to Kathy Buhl, and Laura Gerace for their technical assistance and Brenda Sinclair for her contributions related to nutritional aspects of the study. Lastly, we are fortunate to have a great staff at the Center for Sports Medicine/Noll Physiological Research Center and would like to thank all of clinical and technical staff for their help in data collection, medical monitoring, and nutritional support.
Current affiliations for Susan M. Puhl: State University of New York at Cortland, Park Center E-253, Box 2000, Cortland, NY 13045; N. Travis Triplett-McBride and Jeffrey M. McBride at the University of Wisconsin-LaCrosse, LaCrosse, WI 54601; Keijo Häkkinen, University of Jyväskylä, Jyväskylä, Finland; and L. Perry Koziris, Department of Kinesiology, North Texas State University, Denton, TX.
Address for correspondence: William J. Kraemer, Ph.D., Professor/Director, The Human Performance Laboratory, Ball State University, Muncie, IN 47306. E-mail: email@example.com.