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.