Video shows what sporophyte means. A plant (or the diploid phase in its life cycle) which produces spores by meiosis in order to produce gametophytes.. Sporo...
Concentric contraction involves a shortening of the muscles under loading and is used to accelerate the body or move an object, as when you suddenly move in the opposite direction to hit the baseball.
It's a training method based on the understanding that a concentric muscular contraction is much stronger if it immediately follows and eccentric contraction of the same muscle.