Elevated metabolic rate during passive stretching is not a sufficient aerobic warm-up

PurposeThe purpose of this study was to determine the extent that a static stretching program could increase heart rate (HR) and oxygen consumption (VO2), and if the increases were sufficient to serve as a warm-up for aerobic activity.MethodsThe HR and VO2 of 15 male and 16 female college students were measured after either 12 min of passive static stretching (SS), or 12 min pseudo-stretching (PS), which consisted of moving through the stretching positions without placing the muscles on stretch. Four different lower body stretches were used with each stretch held for 30 s before the participant moved to a different position, with the circuit being repeated four times. VO2 was determined by averaging breath-by-breath measures over the total 12 min. HR was obtained every 30 s and the 24 values were averaged. Warm-up benefit was determined from the O2 deficit accrued during 7-min cycling at 60% VO2max.ResultsHR (beats/min, mean ± SD) for SS (84 ± 11) was a significant (p < 0.05) 9% greater than PS (78 ± 12). Similarly, VO2 (mL/min, mean ± SD) for SS (0.53 ± 0.13) was a significant 44% greater than PS (0.38 ± 0.11). The O2 deficit (L, mean ± SD) for SS (0.64 ± 1.54) was not different from PS (0.72 ± 1.61).ConclusionThese data indicate that passive static stretching increases both HR and VO2, indicating that metabolic activity can be increased without muscle activation. The magnitude of the increases, however, is not sufficient to elicit a warm-up effect.