Eccentric squat strength predicts vertical jump performance

Some regard the counter-movement jump (i.e., vertical jump) as the greatest predictor of athletic performance in field and court sports such as soccer, football and basketball. The counter-movement jump is effected by both relative strength and explosive power, both of which are key components of athletic movements such as sprinting, and changing direction. The counter-movement jump is often used as a testing tool to monitor the effects of training as well as to keep tabs on fatigue. For example, a training program can be considered successful if counter-movement jump performance is improving. Conversely, if counter-movement jump performance is stagnating or regressing, it may be due to fatigue, injury or training staleness. Given the importance that many coaches place on the vertical jump, understanding how it can be improved with training is needed to guide programming.

A new study published ahead of print in the Journal of Strength and Conditioning Research evaluated relationships between concentric and eccentric peak force during squatting and vertical jump performance in resistance trained males. Twelve 25-year-old men (~177 cm in height, ~84 kg in weight) were tested for peak force during concentric and eccentric squatting using an Exerbotic squat device. Subjects were also tested for peak power and peak ground reaction force and height from a series of 3 counter-movement jumps on a force plate. Relationships between variables were quantified with Pearson correlation coefficients.

The results showed a large and significant relationship between absolute concentric peak force and absolute counter-movement jump peak power (r = 0.66). Additionally, a very large and significant relationship was found between absolute eccentric peak force and absolute counter-movement jump peak power and height (r = 0.74 and 0.74, respectively). Relative eccentric peak force also demonstrated a very large relationship with peak power and height from the counter-movement jumps (r = 0.73 and 0.79, respectively). Since eccentric force provided the strongest predictive ability of vertical jump performance, the authors suggest that coaches should include exercise that enhance lower body eccentric strength.

Reference:

Bridgeman, LA. et al. (2016) Relationships Between Concentric and Eccentric Strength and Countermovement Jump Performance in Resistance Trained Men. J Str Cond Res. In Press.