Lower body versus whole body resistive exercise training and energy requirements of older men and women.

A person's energy requirement is defined as the metabolizable energy intake (MEI) consumed over a period of body weight stability. Controversy exists regarding whether resistive exercise training (RT) influences the energy requirement of older people. The aim of this study was to assess the effect of RT on the energy requirement of older people. The subjects were 11 men (M) and 17 women (W); age range, 55 to 78 years. During a 14-week precisely controlled diet study, each subject consumed foods and beverages portioned to provide sufficient MEI to match their energy requirement and to keep body weight stable at +/- 0.5 kg of their starting weight. MEI was determined from bomb calorimeter analyses of the gross energy (GE) content of food, urine, and feces samples collected during 4-day intake-balance periods at study weeks 2, 8, and 14 (baseline, week RT6, and week RT12, respectively). MEI = GE(food)-GE(urine) - GE(feces). Resting energy expenditure (REE) was measured using an indirect calorimeter. From study weeks 3 to 14, 10 subjects (4 M, 6 W) remained sedentary (SED), 9 subjects (4 M, 5 W) performed lower body RT (LBRT) 3 times/week, and 9 subjects (3 M, 6 W) performed whole body RT (WBRT) 3 times/week. Body weight was not different among the SED, LBRT, and WBRT groups at baseline and were not changed over time or influenced by RT. At baseline, MEI was not different among the 3 groups. From weeks RT1 to RT12, MEI had to be increased by 17% +/- 5% (mean +/- SEM), 14% +/- 7%, and 12% +/- 7% in the SED, LBRT, and WBRT groups, respectively, to maintain stable body weights. At week RT12, the MEI required to maintain stable body weight was not significantly different among the SED, LBRT, and WBRT groups (9.45 +/- 0.95, 9.40 +/- 0.83, and 8.64 +/-0.53 MJ/d, respectively). At week RT12, the MEI and MEI/REE ratio were higher in men versus women, independent of group assignment. These data suggest that RT, whether performed using the lower body only or the whole body, does not increase the energy requirement of older people. Also, these data show that the energy requirement of older men is greater than that of older women.

Duke Scholars

Author William Joseph Evans Medicine, Geriatrics