Effects of detraining on cardiorespiratory fitness of individuals with chronic stroke

Background Aerobic training can improve cardiorespiratory fitness in individuals after stroke. However, the effects of short-term and long-term detraining are not well known. Objective To determine the effects of short-term (1-month) and long-term (6-month) detraining on cardiorespiratory fitness (VO2peak) of individuals after stroke, who participated in aerobic training. Methods A cohort study was developed. Twenty adults (57 +/- 11 years old) with stroke were included. After completing an outpatient aerobic training, participants were divided into gain group (VO(2peak)increase >1.3 ml.kg(-1).min(-1)from before to immediately after the training) or non-gain group (VO(2peak)change <= 1.3 ml.kg(-1).min(-1)). Cardiorespiratory fitness (VO2peak), obtained by the cardiopulmonary exercise test was assessed one and 6 months after the end of the training (short- and long-term detraining, respectively), or collected retrospectively from patient chart (before and after the training). Results There was found a significant interaction effect (time*group) for VO2peak(F= 6.108;p < 0,001). Higher values in the VO(2peak)observed in the gain group with the aerobic training (F = 25.86;p< .001) were significantly reduced with short-term detraining, reaching values similar to that observed before the training and to that of the non-gain group (F = 14.81;p= .001). Both groups had similar VO(2peak)values within long-term detraining (F = 2.70;p= .12), with no significant differences from the values observed before the training and after short-term detraining (0.11 <= p <= 1.00). Conclusions Detraining on cardiorespiratory fitness of individuals after chronic stroke occurred within only 1 month. Therefore, it is important to maintain aerobic training throughout life.