We tested the hypothesis that static stretching, an acute, non-metabolic fatiguing intervention, reduces exercise tolerance by increasing muscle activation and affecting muscle bioenergetics during cycling in the "severe" intensity domain. Ten active men (24±2 years, 74±11 kg, 176±8 cm) repeated an identical constant load cycling test, two tests were done in control conditions and two after stretching, that caused a 5% reduction of maximal isokinetic sprinting power output. We measured: i) oxygen consumption (VO2); ii) electromyography: iii) deoxyhemoglobin iv) blood lactate ([La-]); v) time to exhaustion (TTE) vi) perception of effort. Finally, VO2 and deoxyhemoglobin kinetics were determined. Force reduction following stretching was accompanied by augmented muscle excitation at a given workload (p=0.025), and a significant reduction in TTE (p=0.002). The time to peak of VO2 was reduced by stretching (p=0.034), suggesting an influence of the increased muscle excitation on the VO2 kinetics. Moreover, stretching was associated with a mismatch between O2 delivery and utilization during the on-kinetic, increased perception of effort and [La-], that are all compatible with an increased contribution of the glycolytic energy system to sustain the same absolute intensity. These results suggest a link between exercise intolerance and the decreased ability to produce force. Novelty bullets: • We provided the first characterization of the effects of prolonged stretching on the metabolic response during severe cycling. • Stretching reduced maximal force, augmented muscle activation in turn increasing the metabolic response to sustain exercise.

Prolonged static stretching causes acute, non-metabolic fatigue and impairs exercise tolerance during severe intensity cycling

Colosio, Alessandro L;Teso, Massimo;Pogliaghi, Silvia
2020-01-01

Abstract

We tested the hypothesis that static stretching, an acute, non-metabolic fatiguing intervention, reduces exercise tolerance by increasing muscle activation and affecting muscle bioenergetics during cycling in the "severe" intensity domain. Ten active men (24±2 years, 74±11 kg, 176±8 cm) repeated an identical constant load cycling test, two tests were done in control conditions and two after stretching, that caused a 5% reduction of maximal isokinetic sprinting power output. We measured: i) oxygen consumption (VO2); ii) electromyography: iii) deoxyhemoglobin iv) blood lactate ([La-]); v) time to exhaustion (TTE) vi) perception of effort. Finally, VO2 and deoxyhemoglobin kinetics were determined. Force reduction following stretching was accompanied by augmented muscle excitation at a given workload (p=0.025), and a significant reduction in TTE (p=0.002). The time to peak of VO2 was reduced by stretching (p=0.034), suggesting an influence of the increased muscle excitation on the VO2 kinetics. Moreover, stretching was associated with a mismatch between O2 delivery and utilization during the on-kinetic, increased perception of effort and [La-], that are all compatible with an increased contribution of the glycolytic energy system to sustain the same absolute intensity. These results suggest a link between exercise intolerance and the decreased ability to produce force. Novelty bullets: • We provided the first characterization of the effects of prolonged stretching on the metabolic response during severe cycling. • Stretching reduced maximal force, augmented muscle activation in turn increasing the metabolic response to sustain exercise.
2020
oxygen consumption
V̇O2 slow component
exercise tolerance
stretching
muscle stretching
loss of efficiency
muscle fatigue
V̇O2 kinetics
NIRS
EMG
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/1013840
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