In this study we report the effects of training at intensities below and above the lactate threshold on parameters of aerobic function in elderly subjects (age range 65-75 yr). The subjects were randomized intp high-intensity (HI, N = 8; 75% of heart rate reserve = |82% VO2max = |121% of lactate threshold) and low-intensity (LI, N = 9; 35% of heart rate reserve = -53% VO2max, = |72% of lactate threshold) training groups which trained 4 d-wk-1 for 30 min-session-1 for 8 wk. Before and after the training, subjects performed an incremental exercise test for determination of maximal aerobic power (VO2max) and lactate threshold (LT). In addition, the subjects performed a 6-min single-stage exercise test at >75% of pre-training VO2max (SST-High) during which cardiorespiratory responses were evaluated each minute of the test. After training, the improvements in VO2max (7%) for LI and HI were not different from one another (D VO2max for LI = 1.8 ± 0.7 ml-kg-1 min-1; D VO2max, for HI = 1.8 ± 1.0 ml-kg-1 min-1) but were significantly greater (P = 0.02) than the post-testing change observed in the control group (N = 8). Training improved the LT significantly (10— 12%; P< 0.01) and equally for both LI and HI (ALT for LI = 2.3 ± 6 ml Oj-kg-1-min-1; DLT for HI = 1.8 ± 0.8 ml (Vkg-1-min"'). In comparison with controls, during the post-training SST-High for LI and HI, there were significant training-induced reductions in the exercise heart rate, VE, and VCO2. These results demonstrate that, for previously sedentary elderly subjects, 8 wk of low-intensity training (i.e., below the LT) provide comparable increases in VO2max and LT and decreases in cardiorespiratory responses to high-intensity exercise, as compared with 8 wk of high-intensity training (i.e., above the LT). We conclude that low-intensity, sub-LT walking training (as defined herein) is an adequate aerobic training stimulus for producing modest gains in aerobic power in previously sedentary elderly subjects.
- Aerobic power
- Heart rate
- Physical training
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation