We have developed an apparatus whereby the repel force produced by the exertion of force on the start-grips at the start time can be measured and displayed on a large LED matrix display. Using this apparatus, athletes can train themselves while confirming their exertion of grip force. This apparatus also has the function of measuring the time between 2 points on the course and displaying the interval time. Since wave patterns are saved in a computer, useful information can be obtained by data processing. Using those data, we examined and compared the athletes' patterns of force exertion. As a result, maximum force and the degree of impulse were observed to be correlated with interval time. Therefore, in general, athletes with good interval time had rather stable wave patterns.
