Why the full range of motion?

We've all seen that person in the squat rack basically bobbing up and down, not engaging in the full range of motion..and we all tend to be a little judgmental about it (to put it politely) However, why is ass to grass better? Read up on this and you'll truly appreciate a full squat. Knowledge is power. 

You can place mechanical tension on a muscle by doing 2 things, combined. One of these is called passive elastic tension which is basically stretching a muscle without letting it contract. The other is called isometric contraction and this is basically flexing the muscle. When we lift through the full range of motion we combine these two - the muscle is being stretched whilst being activated. Research (that I'll reveal below) shows that one of these factors alone is not key to building maximum muscle, but it is the two combined that will optimally allow you to achieve your muscle goals.

A common misconception is that by lowering the range of movement, we can load more weights, meaning more resistance and therefore more muscle growth. However, this ignores the fact that the net movement is product of the external barbell load as well as the length of the muscle. Therefore, a heavier weight can provide just as much stress as a lower weight with full muscle contraction.

A study was carried out on 2 test groups. Both groups did a leg workout 3x a week, one group at 0-50 degree angles, the other 50-90 degree angles. Long story short, the group which used to larger range of motion had larger muscle growth by the 12th week. 

Another study focused on upper body training, 3 groups we're assigned different extremes of muscle contraction. The first group were partial contraction, the second full contraction and the third was simply a control group. The subjects trained 2 days a week for 10 weeks, their progress was measured by one rep maximums on the 10th week. Both the partial and full contraction subjects one rep max increased. However, the partial contraction group only by 6.7-16%, compared to the full contraction group who's one rep max increased by 9.6-25.6%. Muscle thickness increased up to 9.65% in full contraction, compared to a max increase of 7.8% in part contraction. Indicating that muscle thickness and strength can be increased by both methods but is greater when using FULL contraction. 

Another thing I found interesting is that study was carried out to examine the molecular signals due to contracted or stretched muscles. (this applies in that a stretched muscle would be using the full range of motion) The study showed that a stretched muscle releases more IGF-1 which is a growth factor and is a key mediating factor for stretch-mediated muscular hypertrophy. (MUSCLE GAINZ) 

I hope you found my post interesting! Keep squatting deep. Peace out.