Resistance exercise and physical performance in adults aged 60 to 83.

OBJECTIVES: This investigation examined the effect of 6 months of high- or low-intensity resistance exercise on muscular strength and endurance and stair climbing ability in adults aged 60 to 83. DESIGN: A randomized controlled trial. SETTING: University of Florida Center for Exercise Science. PARTICIPANTS: Sixty-two men and women completed the study protocol. Subjects were matched for strength and randomly assigned to a control (n = 16), low-intensity (LEX, n = 24), or high-intensity (HEX, n = 22) group. INTERVENTION: Six months of progressive, whole-body resistance training. Subjects trained at 50% of their one-repetition maximum (1RM) for 13 repetitions (LEX) or 80% of 1RM for eight repetitions (HEX) three times per week for 24 weeks using resistance machines. One set each of 12 exercises was performed. MEASUREMENTS: One-repetition maximum was measured for eight different exercises. Muscular endurance was measured using leg press and chest press machines. Low back strength was measured using a lumbar extension machine. Stair climbing ability was assessed as the time to ascend one flight of stairs. RESULTS: 1RM significantly increased for all exercises tested for the HEX and LEX groups (P < or =.050). The increases in total strength (sum of all eight 1RMs) were 17.2% and 17.8% for the LEX and HEX groups, respectively. Muscular endurance improved by 79.2% and 105.0% for the leg press, and 75.5% and 68.0% for the chest press for the LEX and HEX groups, respectively. The time to ascend one flight of stairs significantly decreased for both the LEX and HEX groups (P < or =.050). Lumbar extension strength increased by 62.6% and 39.5% for the LEX and HEX groups, respectively. CONCLUSIONS: These data indicate that significant and similar improvements in strength, endurance, and stair climbing time can be obtained in older adults as a consequence of high- or low-intensity resistance exercise training. These findings may have an effect on how resistance exercise is prescribed to older adults.

Improved cardiorespiratory endurance following 6 months of resistance exercise in elderly men and women.

OBJECTIVE: To examine the effect of 6 months of high- or low-intensity resistance exercise on aerobic capacity and treadmill time to exhaustion in adults aged 60 to 83 years. METHODS: Sixty-two men and women completed the study protocol. Subjects were matched for strength and randomly assigned to a control (n = 16), low-intensity exercise (LEX, n = 24), or high-intensity exercise (HEX, n = 22) group. Subjects trained at either 50% of their one repetition maximum (1-RM) for 13 repetitions (LEX) or 80% of 1-RM for 8 repetitions (HEX) 3 times per week for 24 weeks. One set each of 12 exercises was performed. Strength was measured for the leg press, chest press, leg curl, leg extension, overhead press, biceps curl, seated row, and triceps dip. Muscular endurance was measured for the leg press and chest press. Aerobic capacity (peak oxygen consumption [VO(2)peak]) was measured during an incremental treadmill test (Naughton). Treadmill time to exhaustion was measured as the time to exhaustion during the incremental exercise test. RESULTS: The 1-RM significantly increased (P< or =.05) for all exercises tested for both the HEX and LEX groups. Aerobic capacity increased (P< or =.05) by 23.5% (20.2 to 24.7 mL x kg(-1) x min(-1)) and by 20.1% (20.9 to 24.4 mL x kg(-1) x min(-1)) for the LEX and HEX groups, respectively. Treadmill time increased (P< or =.05) by 26.4% and 23.3% for the LEX and HEX groups, respectively. CONCLUSIONS: Significant improvements in aerobic capacity and treadmill time to exhaustion can be obtained in older adults as a consequence of either high- or low-intensity resistance exercise. These findings suggest that increased strength, as a consequence of resistance exercise training, may allow older adults to reach and/or improve their aerobic capacity.