This week we are featuring a track and field based drill commonly mis-prescribed by trainers.
Have you have seen or tried such a high box jump that makes you second guess your choice mid jump? If not, good on you, but have you ever seen someone else attempt a box jump so high, or with such bad form, it makes you second guess THEIR choice?
What is the purpose of pushing your luck on a borderline-dangerous high box jump?
I would argue, ego.
Mechanics of jumping on something that high takes away the point of jumping exercises in the first place. The point of jumping exercises will hopefully be conveyed in this post, as they encompass one or more of the following:
1) Training the stretch-shorten-cycle reflex. This reflex is a physiological response to a quick stretch of the muscle and tendon, and if done correctly, can increase your vertical jump or quicken your response to a stimulus. How does it work? The quick stretch in the muscle during the quick loading prior to jumping, stretches "muscle spindles" in the muscle which neurologically cause the muscle to contract and shorten thereafter. To read more on the muscle physiology concepts, see this post.
2) Training stiffness. A key element of getting this exercise right is maintenance of quad and hamstring co-contraction (tightening them at the same time). The tighter and stiffer the muscles can be kept, the more the energy will be dissipated and utilized in the tendons.... free energy!
3) Training coordination. It may not seem like it - but I am 99% sure that when you try this for the first time over hurdles or cones spaced out by 1.25-1.5m apart, you will miss-predict the spacing of your jumps, and look like you're flailing (yes, even you elite athletes reading this, if you haven't tried it!). The vertical rebound at the end of the hurdles is an important spacing/coordination element of the series, rather than relaxing at the end of the series.
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