They will then grow to master the roll over on their back a few weeks later as this requires more muscle strength from the arms, neck and back. (bounty.com)
This could result in more muscle strength when you do the exercises that have the most activation. (verywellfit.com)
In the studies done on a group of NCAA football players, the ZMA group showed 250 % more muscle strength gain than the placebo group, but in actual strength gains, the ZMA group showed 11.6 % compared to 4.6 % for the placebo group. (bodybuildingforyou.com)