The aim of this study is to use ground contact times determined by inertial measurement units to find out if contact times in the high jump are related to performance. Furthermore, it is investigated how constant the contact times of the approach in high jump is and whether there are similarities to long jump. Three already experienced athletes were equipped with IMUs on the outer ankles of the foot and performed a total of 23 attempts within one training session in high jump. Two of them also performed 9 attempts within one training session in long jump with these sensors. The standard deviation of the ground contact times shows a rather less constant approach for one athlete and an already relatively regular run-up for the other two athletes. The correlation of ground contact times with the height achieved is calculated. The difference in the correlation of the individual athletes is significantly large. The strongest correlation is -0.90, while the strongest correlation of another athlete is only -0.23. We find that the shorter the contact times the larger the height achieved. However, this only applies up to a certain limit. When comparing the contact times of high jump to long jump there is a similarity because the contact times decreases more and more with each step. The contact times for long jump are always about 0.05 seconds shorter than those for high jump.