The relationship between muscle thickness of leg and trunk and the sprint performance in the field and on the cycle ergometer in high school and college students cyclists / 体力科学

The 30-seconds all-out sprint test on the cycle ergometer was performed by 10 high school and 13 college men’s cyclists. In addition, this study investigated their best time for 200 m (200mTT) and 1000 m (1000mTT) time trials in the velodrome. This study clarifies the relationship between muscle thickness of thigh, shank, and trunk and 1) the average speed for the 200mTT and 2) the 1000mTT in the field, and 3) the mean power of the 30-seconds all-out sprint cycling test. 1) The average speed for the 200mTT significantly correlated with the muscle thickness of posterior shank and front and lateral abdomen. 2) The average speed for the 1000mTT significantly correlated with the muscle thickness of posterior thigh and shank and front and lateral abdomen. 3) The mean power of the 30-seconds all-out sprint cycling test significantly correlated with the muscle thickness of anterior and posterior thigh, posterior shank, and front and lateral abdomen. Except for the average speed for the 200mTT and 1000mTT, the mean power of the 30-seconds all-out sprint cycling test was significantly related to the muscle thickness of anterior thigh. These results suggest that increasing muscle thickness of posterior thigh and shank and front and lateral abdomen is important for enhancing performance in sprint cycling.

THE RELATIONSHIP BETWEEN THE RUNNING ECONOMY AND THE HOPPING ECONOMY IN THE LONG DISTANCE RUNNER / 体力科学

Running economy is an important factor in determining a performance of a long distance running. The purpose of this study was to examine the relationship between the running economy and the submaximal hopping economy. Twelve long-distance runners performed a submaximal repeated hopping exercise on a force platform at a frequency of 2.2Hz and the maximum five-repeated rebound jumping (5RJ). Jumping height, contact time, maximum ground reaction force and oxygen intake were recorded during submaximal repeated hopping exercise. In addition, they performed the submaximal running for a distance of 3200m on an outdoor 400m track. Oxygen intake was recorded during the submaximal running. Then running economy (RE = V/VO₂) was calculated by using oxygen intake (VO₂) and running speeds (V). Hopping economy (HE = h/VO₂) was calculated by using oxygen intake (VO₂) and average jumping height (h). As a result of this study, we confirmed that a submaximal repeated hopping exercise performed for a ten-minute period was an aerobic exercise and a steady-state exercise. There was a significant positive correlation between RE and HE (r = 0.805, p＜0.01). These results suggest that hopping economy is an important factor in running economy. On the other hand, we did not find a significant correlation between HE and 5RJ. Furthermore, between RE and RJ index of the submaximal hopping exercise, a significant positive correlation was found (r = 0.735, p＜0.01). Therefore, RE seems to be connected with the Stretch-shortening cycle (SSC) function of the legs. We conclude that the SSC ability of a long distance runner can be evaluated appropriately by using the submaximal repeated hopping exercise of this study.