Abstracts: American College of Sports Medicine Conference on Integrative Physiology of Exercise: SATURDAY, SEPTEMBER 30, 2006: POSTER SESSION 3: Metabolic
Few studies have shown resistance training (RT) to be an effective treatment for weight loss, however; RT may result in both decreased total body and abdominal (trunk) fat with no change in body weight due to increased lean tissue. Reductions in percent body fat (BF) and trunk fat tissue have been associated with decreased cardiovascular disease risk.
To determine the effects of 6 months of RT on body weight, BF, total and regional fat tissue, and total body and regional lean tissue in young men and women.
Fifty-five overweight (BMI= 27.3 ± 2.8 kg/m2), weight stable (<2.2 kg weight change in last 6 months), sedentary (<500 Kcal/wk in leisure time physical activity) individuals (25 females (F), 30 males (M), age= 20.5 ± 2.6 yrs) were randomly assigned to RT (n= 32, 15 F, 17 M) or control (CON, n= 23, 10 F, 13 M). RT consisted of 1 set of 9 weight stack machine exercises (6 upper and 3 lower body exercises) at 3-6 repetition maximum, under direct supervision, 3 days/wk for 6 months. Body weight (calibrated scale), BF, total and regional fat tissue, and total and regional lean tissue (dual-energy X-ray absorptiometry) were assessed at baseline and following 6 months of RT. Data for M and F were analyzed separately.
In M, there were no significant between group changes for body weight (RT=+3.6 ± 4.6 kg, CON=+3.0 ± 2.6 kg (p= 0.64)), BF (RT=+1.08 ± 3.70%, CON=+2.71 ± 2.38% (p= 0.16)), and total fat tissue (RT=+0.95 ± 4.38 kg, CON=+3.79 ± 4.08 kg (p= 0.25)). However, significant between group changes were observed in M for total lean tissue (RT=+1.49 ± 2.46 kg, CON=−0.45 ± 1.08 kg (p= 0.008)). In F, there were no significant between group changes for body weight (RT=+0.7 ± 4.2 kg, CON=+0.7 ± 1.9 kg (p= 0.97). However, significant between group changes were observed in F for BF (RT=−1.32 ± 3.1%, CON=+0.76 ±1.6% (p= 0.040)), leg lean tissue (RT=+0.56 ± 0.71 kg, CON=−0.21 ± 0.53 kg (p=0.049)), trunk fat tissue (RT=− 0.68 ± 2.13 kg, CON=+ 0.91 ± 1.21 kg (p=0.026)), and total body lean tissue (RT=+1.40 ± 1.23 kg, CON=− 0.14 ± 1.23 kg (p=0.006)).
These results suggest that in young, overweight, sedentary F, 6 months of supervised RT results in significant changes in body composition that are associated with decreased cardiovascular disease risk without significant changes in body weight. In M, RT resulted in an significant increase in total body lean tissue but did not result in significant changes in body weight, BF, or total body fat tissue suggesting a potential gender difference in the body composition response to RT in young, sedentary, overweight individuals. Supported by NIH Grant DK62832.