USAWA

By Dan Wagman, Ph.D., C.S.C.S.

THE GUESSING GAME – BOX SQUATS

Part II: Less Guesswork

“The progressive evolution of athletic performance and specific conditioning techniques is dependent on a thorough understanding of those mechanisms underlying dynamic muscular function.”(2)

 

In Part I, I presented someone’s guess that has huge intuitive appeal—that the box squat will enhance your squat strength and power for driving out of the hole. I made a guess, too, and to derive at it I asked what is perhaps the most important question anybody can ask about any training concept: by what physiological mechanism would that idea work? I could find none. The question is, might there be something going on that’s less well understood about muscle contraction mechanisms that might render the box squat a useful tool after all?

Our knowledge of how important the coupling and amortization phases (see Part I) are to you being able to produce maximal strength goes back to research published in 1931.(1) Back then, however, those phase-terms were not used. Since then research has built upon itself and advanced our knowledge of what we now term the stretch-shortening cycle. What all this scientific study would suggest is that the promise that performing box squats will enhance your regular squat is nonsense. But I wanted to verify or refute my “guess” based specifically on research that looked at the squat and box squat.

 

A First Look

I believe the best starting point to be research published in 1998.(2) The researchers recruited 40 athletes of various sports. They all had a minimum of 1 year squatting experience and could squat a minimum of 1.5 times their body weight. The entirety of testing methods are too complex to mention here, but to briefly illustrate included a modified Smith machine that measured and controlled speed of movement, among other things; a force plate to gather much data on force, power, work, etc.; electromyography to measure muscle contractions; and more.

The subjects were tested in three conditions: 1. They had to squat from the bottom position up, similar to a box squat. What was dissimilar to a box squat was that they had to first hold an isometric contraction for no more than 1.5 seconds before exploding upward; 2. The “stretch-shortening squat” was tested, which you may view as a normal competition squat with an intact coupling and optimized amortization phase; 3. The subjects had to perform a maximal isometric contraction against an immovable bar for 100 to 200 milliseconds before it automatically released and allowed the athletes to explode out of the hole.

Among many data points analyzed, the most important consideration for the strength athlete is that the greatest effect on the squat was achieved in the stretch-shortening condition, i.e., a regular squat. That was followed by the squat preceded by a maximal isometric contraction and lastly by squatting from the bottom up as in a box squat, which resulted in the weakest readings. In fact, the readings generated from the standard squat were more than twice that compared to the box squat style. The research team concluded that the quicker you transition from lowering the bar to exploding upward, the more strength you’ll be able to demonstrate. This finding is entirely in line with what you would expect considering the basics of muscle contraction mechanisms/physiology. Bottom line, you must have an intact coupling phase along with the briefest amortization phase possible. Only then can you expect to demonstrate maximal strength and power.

Still, because this was initial work done on the squat and how different methods of commencing the ascent might influence strength and power, there were a lot of methodological controls put in place. Researchers place a great deal of control into their studies in an effort to eliminate extraneous variables that might influence the outcome. In doing so, they obtain very specific and accurate information. From there, future research builds and looks at additional variables that might have an impact. And so it could be argued that since in this initial work the squat was performed with an empty bar and the speed of ascent could not exceed the 0.4 meters per second set by the modified Smith machine, no matter how hard each athlete tried, the squatting was not as specific to a regular competition squat as necessary for an accurate comparison. Of course the research team acknowledged this while outlining in painstaking detail the reasons for their approach. Moreover, it could be argued that when the subjects commenced the squat from a dead stop without pre-stretch or isometric contraction first, that movement pattern was not exactly the same as what’s generally advised in doing a box squat.

So far things don’t look good for the box squat, but the above concerns may or may not be valid, which means I had to dig deeper into the research advancements. Part III will look at comparisons between the actual box squat and standard squat.

 

References

1. Fenn, W.O., et al. The tension developed by human muscles at different velocities of shortening. American Journal of Physiology. 97:1–14, 1931.
2. Walsche, A., et al. Stretch-shorten cycle compared with isometric preload: contributions to enhanced muscular performance. Journal of Applied Physiology. 84(1):97–106, 1998.