Acute passive stretching alters ventilatory pattern during prolonged cycle exercise

Passive stretching may induce the activation of receptors on the terminal end of group III and IV nerve fibers located within joints and muscles through mechanical and chemical stimuli. The aim of the study was to assess the effects of an acute bout of passive stretching on the ventilatory pattern during exercise. Maximum oxygen uptake (VO2max) was determined in nine participants who then performed a sustained cycle exercise of high intensity (85% of VO2max, W85) up to exhaustion, with and without previous stretching administration (on different days, in random order). During the tests metabolic and respiratory parameters were recorded breath-by-breath. Time to exhaustion in the W85 test was significantly shorter (−29%) with stretching. During the first 12 minutes of exercise the following parameters were significantly higher with stretching than without: VO2 (+4%), VE (+9%), respiratory muscle power (+16%) and respiratory muscle VO2 (+13%). The increase in VE was accompanied mainly by an increase in respiratory frequency rather than in tidal volume. Stretching altered the respiratory and metabolic response to exercise Whether the higher VE during exercise after stretching is a consequence of higher muscle afferent activation or higher metabolic rate, though, requires further investigation., but its effects on VE need further investigation.