出版社：Japan Society of Physical Education, Health and Sport Sciences
摘要：In 1920s, A.V. Hill and his coworkers had introduced an excellent electrical timing method to measure the speed of running. The present authors employed an equipment with Cadmiun-cells connected up in series with a galvanometer near the running track. A runner passed across the beam of the light directed to the Cadmium-cells placed at 1, 2, 3, 5, 10, 15, 20, 25, 30, 40, 50,……, 100 meters from the starting point. Each time the subject passed one of the beams of the light, the Cadmium-cell induced a current, which was recorded on the paper of the galvanometer. The stibjects consisted of 407 boys from age 6 to 20, 318 girls from age 6 to 18, as well as 47 male and 6 female sprinters of Japan. Boys and girls from age 6 to were asked to run 50meters, and others 100 meters. The study and the discussion were focused on three points as the followings: 1) Propelling force : The propelling force was calculated directly from the distancetime relation. It was found that the propelling force was improved in advancing of age closely related to the development of the muscular strength. The propelling force of sprinters calculated here coincided fairly with the result by A.V. Hill; and it was double that of ordinary persons. 2) The maximum speed: The maximum speed was found to be closely related to the muscular strength with age. The best record of male sprinters was 10.53 meters per second at the top speed, and that of female sprinters was 8,8 meters per second, while in ordinary boys 8, in ordinary girls 6 meters per second of the same age. 3) Rate of deceleration: The decrease of speed of running was presented by per contage of the maximum speed at the end of running. The speed of thhe last 10 meters of 50 meters running was decreased by l0% or less in boys and girls from 6 to 11. The speed of the last 10 meters of 100 meters running was decreased by l0% or less in boys over 12 years of age, while by 12-14% in girls of the same age.
