Effects of exercise intensity on the stretch-shortening cycle function of the lower limbs after cycling
- VernacularTitle:運動強度の違いが自転車運動後の下肢における伸張－短縮サイクル遂行機能に及ぼす影響
- Author:
Keigo TAKAHASHI
1
;
Yusuke SHIRAI
2
;
Yoshiharu NABEKURA
3
Author Information
- Keywords: reactive strength index; cycling; exercise intensity; metabolic stress; triathlete
- From:Japanese Journal of Physical Fitness and Sports Medicine 2020;69(5):371-381
- CountryJapan
- Language:Japanese
- Abstract: This study aimed to elucidate the effects of exercise intensity on stretch-shortening cycle (SSC) function of the lower limbs after cycling. Ten male triathletes performed a cycling graded test to determine the ventilatory threshold (VT) and two hopping-cycling (30 min of cycling at 90 or 110% VT)-hopping tests. The two hopping-cycling-hopping tests performed in random order. Power output (PO), heart rate (HR) and rate of perceived exertion (RPE) were monitored throughout the 30-min cycling. Blood lactate concentrations (BLa) were measured in order to assess metabolic stress. The SSC function was calculated as the ratio of the jump height to the time spent in contact with the ground (reactive strength index [RSI]). PO, HR and RPE values during cycling at 110%VT was higher than at 90%VT (p < 0.01). BLa value after the cycling at 110%VT was higher than at 90%VT (90%VT: 2.4±1.0 vs. 110%VT: 5.9±2.8 mmol/L, p < 0.01). Regardless of the cycling exercise intensity, the RSI significantly decreased after the cycling exercise (p < 0.01). The RSI remained decreased at 15 min after the cycling exercise (p < 0.05). These results demonstrated that the SSC function decreased after cycling. Exercise intensity during cycling is likely to have no effect on the decrease in SSC function.
