Why do karate classes need to warm up?
According to John Jerome in The Sweet Spot in Time (Touchstone, 1989), “When a muscle is contracted or stretched its temperature rises. In dynamic exercise, up to 80 percent of the energy that is chemically available to the muscle becomes converted into heat. As the muscle heats up it becomes, within limits, stronger and more efficient. The strength of the contraction increases, also within limits, with repeated stimulation of the muscle fiber, in part because of the beneficial effect of increased tissue temperature. Warm muscle fibers simply slide over each other more easily than cold ones.” He goes on to say, “…teams have found that static stretching helps to avoid muscle pulls and cramps, muscles soreness can be diminished by stretching before activity and after activity is over.
