Few data are available about post-exercise recovery (PR) and the aging process. Recovery of VO2, VCO2, V E and HR was observed at different exercise loads (EL) on cyclo-ergometer. A group of 10 young (GJ, age = 22 ± 2 years) and 10 elderly subjects (GI, age = 61 ± 1 years) performed maximal tests. A 30 W/min load incremental was applied to GJ and a 25 W/min after steady-state for GI. Also, subjects performed exercise at 40% and 75% of peak VO2, during 25 and 15 minutes respectively. VO2, VCO2, V E and HR were measured during the first 15 minutes of PR for the three EL. Results analysis was made by: a) testing experimental data residuals for one and two exponential equations; b) determining the better equation components; c) analysis of extracted constants. Deviations were smaller for a two exponential function, defined by S = 0ò¥ x(t)dt = A/a + B/b. A/a designs PR fast component and B/b the slower one. When groups were compared, GI had higher constants than GJ, showing a slower recovery at both phases. GI and GJ constants for PR fast phase (1/a) were similar at all EI for VO2 and VCO2. Results suggested a greater dependence of exercise load for PR slower constant (1/b) in GI. HR recovery has shown to be very much associated to EL in GJ, with time course PR being directly affected by exercise load. The same results were not observed for GI, maybe because of elderly limited HR upward drift potential. Data for V E recovery were similar to those observed for VO2 and VCO2 in GJ. However, GI constants were slower, more associated to EL than the other parameters. The authors conclude that: a) there can be a common constant for the 'alatic phase' of PR for VO2 and VCO2, independent of EL and age; b) differences between GJ and GI can be due to lower maximal aerobic capacity, thermoregulation and age-related reduced CO2 chemosensitivity, delaying elimination of the exercise-induced CO2 load.
Physical activity; Effort test; Elderly; Aging; Recovery; Exercise
