Squat Depth: Part 3 – Optimizing for Performance

In this final installment of determining squat depth, the focus is on how to optimize depth for athletic performance. When determining the effect of a variable on athletic performance, directly relating to specific sport skills are not always practical. Instead, studies will commonly look at specific physical competencies that relate to superior athletic performance. Common tests used are: jump variations, sprint velocities over different distances, cardiovascular performance and strength testing. 

When generalizing testing results to an individual’s athletic ability, Rhea et al (2016) found that quarter squats have a greater transfer to jump and sprint performance, compared to parallel and deep squats. This was attributed to the fact that most athletes will be working in shallower knee and hip flexion positions during these sport specific actions such as jumping and sprinting. Domire & Challice (2007) support this in finding that, despite their computer model indicating that jump height should be highest with a deeper squat depth, results from their subjects tested found no difference in jump height between preferred (shallower) and deep squats. These results support the prominent concept in training of the Principle of Specificity or Specific Adaptations to Imposed Demands (SAID). Rhea et al (2016) summarizes well in saying that “Strength improvements occur at or near joint angles where training occurs.” Considering this, ideal squat depth could vary for many sports, from a powerlifter or weightlifter having to reach the very bottom of a squat to a sprinter having to create as much force as possible in a short time period through shallow joint angles.

Another aspect that must be considered, is what the training program is trying to achieve. For example, early in an off-season, the main priority is getting the athlete back into the swing of things and working through different ranges, less so on priming them for sport specific actions. At this point , just because a jumping athlete may improve their in-season performance most with shallower squats (Rhea et al, 2016), it may be more beneficial for them to work a little deeper to increase range of motion and stability of the joint. In unpredictable sports like hockey, the athlete is not always in their preferred squat depth. Therefore, they also need to work in weaker/deeper/shallower ranges even if that is not going to have the greatest impact on pure skating velocity.

Athletic performance is commonly the result of two factors at the muscular level, motor unit recruitment (how much/many muscle fibers are used for an action) and the rate of force development (how fast the muscles are able to act). Attempting to optimize these two factors makes you consider far more variables than simply, deeper squats allows me to jump higher (greater recruitment) from Domire & Challice’s (2007) model. Based on that finding alone, you could conclude jumping athletes should always squat deep to improve vertical jump height. In quick reaction sports though, like volleyball, the ability to jump high in a split second (rate of force development) is equally as important as peak height. The relationship between power output and the time to produce that power, must constantly be considered.

In conclusion, after looking at injury prevention, muscle activation and optimizing for athletic performance, this topic of ‘determining squat depth’ is multifactorial. It is not as simple as ‘you should always squat deeper’ or ‘you should always squat to knees parallel’ it is highly situational and individual dependant.   

 

References

Domire, Z.J.,  & Challice, J.H. (2007). The Influence of Squat Depth on Maximum Vertical Jump Performance. Journal of Sport Sciences, 25(2), 193-200.

Rhea, M.R., Kenn, J.G., Peterson, M.D., Massey, D., Simao, R., Marin, 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), 43-49.