Negative emotions are a call to action.
In my years of strength coaching, I've had my share of negative emotions. As I became more aware of them, I realized they were there to help me. They did this by forcing me to take action—researching, experimenting and furthering my knowledge so I could avoid these emotions in the future.
I've always been a believer in deep Squats—the lower, the better. I've never been a fan of Half or Quarter Squats, and this showed in the way I trained athletes. We would squat low and we would get strong squatting low.
For example, last fall I started working with a team of Division II baseball players. To estimate explosiveness, I tested their vertical jumps. After two months of heavy strength training (using deep Squats), I retested.
The younger, weaker guys got a lot stronger in those few months—their verticals increased by 3-5 inches.
This agrees with at least three studies: Deep Squats increase jump performance better, have a greater coefficient of transfer, and result in better elevations in jumping than do shallow Squats.
However, the same was not true for the older, stronger athletes.
This group of players also got a lot stronger, but their verticals didn't budge.
As a strength coach whose job is to get guys strong and explosive, this was a negative experience. But it forced me to research, experiment and increase my knowledge, which led me to rethink my philosophy on squat depth.
The following documents a study on squat depth and athletic performance: Twenty-eight college athletes participated in a 16-week study. They were separated into Full, Half and Quarter Squat groups and they would only squat to those depths. The athletes used greater absolute loads with the Half Squats because they were stronger in them. Loads were even greater in Quarter Squats because, again, athletes were stronger when squatting to a higher depth.
They performed four workouts per week (two upper body, two lower body), with the loads increasing from 8RM, 6RM, 4RM and 2RM over the 4 weekly training sessions.
After 16 weeks, the Full Squat group led to the largest gains in Full Squat 1RM; Half Squat led to the largest gains in Half Squat 1RM; and Quarter Squat led to the largest gains in Quarter Squat 1RM.
As for the markers of explosive athleticism, the Quarter Squat group showed the greatest training effect, greatest transfer, and strongest relationship to Vertical Jump and Sprint performance. The Half Squat group was second in these measures and the Full Squat group fell last.
"Taken collectively, these findings support the use of shortened ranges of motion during squat training for improvements in sprint and jump performance among highly trained athletes" the study concluded.
Quarter Squats made athletes more explosive than Half or Deep Squats.
Joint-angle specificity: Quarter Squats more closely match the joint angles seen during jumping and sprinting (in the stance phase). Maybe this explains why Quarter Squats transfer better to these movements, because the joint angles are more specific.
One study reads, "Partial range of motion (ROM) training more optimally loads the terminal ROM where joint angles and movement patterns are similar to those in sport."
Joint-angle overload: Athletes in the study could squat 30-45% more in a Quarter Squat compared to their full Squat. By only training with full Squats and the full squat load, the specific joint-angle (quarter squat position) only gets trained at around 70% of maximum lifting capacity. In highly trained athletes, this is likely not enough load for optimal strength development. To sufficiently overload the Quarter Squat joint angle, athletes must do Quarter Squats separately with a heavier load.
How to Use This to Jump Higher and Sprint Faster
1) Prioritize full Squats until relative strength is developed. Athletes in this study could squat at least 1.5 x their body weight. Younger, weaker athletes probably benefit more from full Squats as they produce greater hypertrophy (muscle size) and strength across all joint angles compared to partial squats.
2) Use a mixture of Squats (e.g., back, front, split) and squat depths (full, half, quarter) to optimize strength development at all joint angles, prevent overuse injuries, and develop total athleticism.
3) Use a belt squat for partial squat training. This decreases excess axial loading and prevents potential injuries involved with loading a heavy bar on your back.
Deep Squats are not the Holy Grail of athletic development. Once your deep Squat is relatively strong, experiment with partial squats and watch your Vertical Jump and sprinting speed reach new levels.
Rhea, M. R., Kenn, J. G., Peterson, M. D., Massey, D., Simão, R., Marín, P. J., Favero, M., Cardozo, D., & Krein, D. (2016). "Joint-angle specific strength adaptations influence improvements in power in highly trained athletes," Human Movement, 17(1), DOI: 10.1515/humo-2016-0006
Rhea, M. R., Alvar, B. A., Burkett, L. N., & Ball, S. D. (2003). "A meta-analysis to determine the dose response for strength development," Medicine and Science in Sports and Exercise, 35(3), 456-64.
McMahon, G. E., Morse, C. I., Burden, A., Winwood, K., & Onambélé, G. L. (2014). "Impact of range of motion during ecologically valid resistance training protocols on muscle size, subcutaneous fat, and strength," Journal of Strength and Conditioning Research, 28(1), 245-55.
Bloomquist, K., Langberg, H., Karlsen, S., Madsgaard, S., Boesen, S., & Raastad, T. (2013). "Effect of range of motion in heavy load squatting on muscle and tendon adaptations," European Journal of Applied Physiology, 113(8), 2133-42.
Weiss, L. W., Fry, A. C., Wood, L. E., Relyea, G. E., & Melton, C. (2000). "Comparative effects of deep versus shallow squat and leg-press training on vertical jumping ability and related factors," Journal of Strength and Conditioning Research, 14(3), 241-7.
Hartmann, H., Wirth, K., Klusemann, M., Dalic, J., Matuschek, C., & Schmidtbleicher, D. (2012). "Influence of squatting depth on jumping performance," Journal of Strength and Conditioning Research, 26(12), 3243-61.