Influence of acute passive stretching on the oxygen uptake vs work rate slope during an incremental cycle test

Purpose The aim of the study was to investigate the effects of acute passive stretching on O2 uptake (˙V O2) vs work rate slope during a continuous incremental ramp exercise. Methods On two different occasions, eight participants (age 23 ± 3 years; stature 1.71 ± 0.10 m; body mass 68 ± 8 kg; mean ± SD) performed two maximum incremental ramp tests on a cycle ergometer (25 W/min), with and without pre-exercise stretching. During tests, we measured ˙V O2 and other metabolic and cardiorespiratory parameters on a breath-by-breath basis. The ˙V O2 vs work rate slopes were calculated below (S1) and above (S2) the first ventilatory threshold (VET1). Results With stretching: (1) peak ˙V O2 did not change, while peak work rate decreased (P < 0.05, ES = −0.41; CI −1.40/−0.58); (2) in spite of a similar S1, S2 was steeper by about 11 % (P < 0.05; ES = 0.62; CI −0.38/−1.62). Conclusions Stretching reduced peak work rate and altered the ˙V O2 vs work rate relationship above VET1 (S2), without affecting peak ˙V O2. The present findings have practical implications, questioning the use of stretching manoeuvres especially when peak work rate plays a key role in exercise performance.