EFFECTS OF INTERVAL TRAINING AT THE VENTILATORY THRESHOLD ON CLINICALAND CARDIORESPIRATORY RESPONSES IN ELDERLY HUMANS

This study assessed clinical and cardiorespiratory responses after an interval training programme in sedentary elderly adults using the vent ilatory threshold (V-th) as the index of exercise training intensity. A selection of 22 subjects were randomized into two groups: II subject s served as the training group (TG) and the others as controls (CG). M aximal exercise tests were performed on a treadmill before (TO), each month (T-1, T-2) and after the 3-month interval training programme per iod (T-3) The TG subjects were individually trained at the heart rate corresponding to V-th measured at T-0, T1 and T-2 as the breakpoint in the oxygen uptake-carbon dioxide production relationship. Their train ing programme consisted of walking/jogging sessions on a running track twice a week. The sessions consisted of varying durations of exercise alternating with active recovery in such a way that the subjects slow ly increased their total exercise time from an initial duration of 30 min to a final duration of 1 h. During training the heart rate was con tinuously monitored by a cardiofrequency meter, Compared with the dail y activities of the controls, no training programme-related injuries w ere observed in TG, Moreover, programme adherence (73%) and attendance (97.3%) were high. The maximal oxygen uptake and V-th were increased in TG, by 20% (P<0.05) and 26% (P<0.01), respectively. Interval traini ng at V-th also significantly increased maximal O-2 pulse (P < 0.05) a nd maximal ventilation (P < 0.01). A significant decrease in submaxima l ventilation (P< 0.05) and heart rate (P < 0.01) was also noted. Thes e results would suggest that for untrained elderly adults, an interval training programme at the intensity of V-th may be well-tolerated cli nically and may significantly improve both maximal aerobic power and s ubmaximal exercise tolerance.