To clarify the competitive characteristics of motor sports, various measurements of physical fitness and also measurements of ability of circulation and stress impinging on drivers during races, etc. were performed. The subjects are 20 racing drivers in F-3, F-3000, Group C, Group A, etc. As for their physical profiles, various capacity tests for locomotion were performed, centering on measurements of isokinetic muscle strength and movement speeds of joints. As a result, no specificity was observed except for excellence in the reaction time. However, there were many cases in which the muscle strength and muscle endurance needed as racing drivers seemed lacking, and a conclusion was drawn that the training for muscle strength and muscle endurance was necessary. Concerning the muscle endurance of the whole body, a stress test using treadmill was performed and VO₂max intake was measured. In consequence the muscle endurance of the whole body was not particularly excellent. The higher the class the more the increasing of competition time and physical load, and resultantly it is necessary to heighten the capacity by training, although there may be cases where no such training is needed depending on races. As the present status, there are many drivers who hardly perform any training, and it can be said that their muscle endurance of whole bodies is inferior to that of other sport players.
　To examine the ability of circulation during races, the ECGs during races were recorded, using a Holter electrocardiograph. Though abnormality in wave form of ECG, arrhythmia, etc. were not observed, heart rates showed very high values at the same time with the start of race and hardly showed any decrease during race. This seems attributable mainly to psychological stress and is a cause different from an increase in heart rate due to muscle locomotion such as marathon.
　Physical loads, borne by drivers during races include changes in acceleration caused by high speed driving as the most important one, and besides elevation in temperature, noise, etc. The measurement with an accelerometer (G-meter) recorded about 1.5 G as acceleration to a horizontal direction as a particularly problematic one, in Group C racing cars. It is said that further greater acceleration is caused in F-1 and F-3000 cars and drivers must endure this acceleration till the completion of race. The temperature differs depending on the kind of racing car but it is said that the inside temperature reaches even 60°C in a Group C racing car, the so-called hottest one, and its driver is likely to fall in dehydration because of excessive sweating under a condition of high temperature. With respect to noise, a very high value of 142 db was shown when a measurement was made in a Group C racing car.

DESCENTE SPORTS SCIENCE Vol.11/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE