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.