Resistance training with dietary intake maintenance increases strength without altering body composition in older women.

BACKGROUND: Evidence suggests that the aging process tends to lead to sarcopenia and osteoporosis which reduce the quality of life in older women. Resistance training (RT) is widely supported as a means of delaying or offsetting the decline in muscle strength and loss of bone mineral content in older women. The purpose of this investigation was to analyze the effects of a 12-wk RT program (3 times a week) with dietary intake maintenance on muscle strength and body composition of healthy, sedentary older women.

METHODS: Forty-four older women were randomly assigned to a RT program (N.=22, 66.3±4.8 years, 60.7±9.1 kg, 153.1±0.90 cm, 24.9±3.3 kg/m²) or a control group (N.=22, 66.4±4.0 years, 63.3±7.5 kg, 155.5±5.8 cm, 26.2±2.6 kg/m²) performing stretching exercises during the same period. One-repetition maximum test on chest press and leg extension were used to assess muscle strength. Body composition was measured by dual energy x-ray absorptiometry to determine fat mass, fat-free mass, and bone mineral content. Dietary intake was recorded using a 3-day food records. All subjects maintained their normal diet during the investigation.

RESULTS: No significant differences were found for the body composition components within and between groups. A significant time by group interaction indicated that the RT group made greater improvements in upper and lower limb muscle strength (chest press ~12%, P=0.0001; leg extension ~13%, P<0.0001).

CONCLUSIONS: These results suggest that RT program improves muscle strength of major muscle groups, without altering body composition in older women under dietary intake maintenance.