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.
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 [V̇O2 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.
The 1-RM significantly increased (P≤.05) for all exercises tested for both the HEX and LEX groups. Aerobic capacity increased (P≤.05) by 23.5% (20.2 to 24.7 mL · kg−1· min−1) and by 20.1% (20.9 to 24.4 mL · kg−1· min−1) for the LEX and HEX groups, respectively. Treadmill time increased (P≤.05) by 26.4% and 23.3% for the LEX and HEX groups, respectively.
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.