(16) A COMPARISON OF COUNTERMOVEMENT JUMP VARIABLES BETWEEN SINGLE SPORT AND MULTIPLE SPORT YOUTH ATHLETES

Young athletes participating in a single sport may have higher rates of drop out and injury. Although, researchers have not examined the performance differences between athletes that participate in one sport versus those that participate in multiple sports.

Purpose: The aim of this study was to determine if there were differences in countermovement jump (CMJ) performance in adolescent athletes participating in a single sport or multiple sports.

Methods: Subjects (n = 53, mean ± SD: age: 15.5 ± 1.5 years, height: 169.1 ± 7.7 cm, mass: 61.8 ± 8.9 kg) performed 3 CMJs on a force plate, with data subsequently analyzed in Excel, using a forward dynamics approach. After a 3-minute warm up on a cycle ergometer and 5-minute lower limb dynamic stretching the subjects completed 3 countermovement jumps (with 30-seconds between each jump). Prior to the recorded jumps the subjects performed practice jumps until the subject had familiarize themselves with the requirements of the jump. The subjects were instructed to place their hands on the hips throughout the movement. The subjects were also instructed that the squat depth was at their discretion, and to jump as high as possible. Once the subjects stepped on the force plate, they stood still for one second so that the subject’s weight could be recorded and to ensure accurate measurements for the movement onset threshold. After the subject was still for at least one second, they were instructed to jump. The variables of interest were consistent with previous work from McMahon et al. (2017) and included jump height, peak and mean propulsive power, propulsion impulse, propulsion mean and peak force, braking mean and peak force. 

Results: CMJ height, relative mean propulsion power and relative propulsive impulse were significantly (p < 0.05) and moderately (g > 0.60) greater in single sport athletes compared to multiple sport athletes. In contrast, relative peak propulsion power, relative mean braking force and relative peak braking force were not significantly different (p > 0.05) between groups, although the single sport athletes performed better, and of a moderately to large magnitude (g 0.654-1.03), compared to the multi-sport athletes. Relative mean propulsion force and relative peak propulsion force were not significantly or meaningfully different between groups (p > 0.05; g < 0.60). 

Conclusion: Single sport athletes that are post - peak height velocity possess superior countermovement jump outputs than the multi-sport athletes with the same maturity status. Therefore, based on these results multi-sport athletes need to ensure they are participating in appropriate and adequate strength and conditioning to support the demands of participating in multiple sports. PRACTICAL APPLICATION: Practitioners and researchers should be aware that single sport athletes outperform multi-sport athletes (post-PHV) when performing the CMJ.  Therefore, based on the results of this study it is shown that early sport specialization in a single sport may results in greater CMJ performance compared to the multiple sport athletes.


Acknowledgements: None