Deep squats are more effective at acutely improving vertical jump than quarter squats.
In a new study, half of the subjects were asked to perform a 3RM on the parallel squat, while the other half were only required to go to a quarter depth. Subjects performed a vertical jump test before and after squatting, and differences were compared between groups.
The authors found that those who had squatted to parallel demonstrated significantly greater improvements in vertical jump compared to those who did not achieve as much depth.
Conclusions
I have always believed that squatting deep with less weight is better than doing shallow squats with more weight, despite the fact that this may be less stimulating to one’s ego. This study lends a slight amount of credence to this belief.
Unfortunately, however, this study only measured acute changes, so it is impossible to assess whether the full squat would have led to superior results over the course of a monthly training program. More research will need to be done to determine if the chronic effects are as pronounced as the acute effects.
References
1 Lowery RP, et al. The effect of potentiating stimuli intensity under varying rest periods on vertical jump performance and power. Journal of Strength and Conditioning Research. 2012 Dec; 26(12): 3320-3325.