The effect of movement on the human body is different, depending on whether it is strong or weak, whether it alternates with rest and whether a person moves a lot or a little - this, according to philosophers, constitutes an independent section - as well as what substance a person is dealing with. Strong movements, frequent and rare, alternating with rest, are similar in that they excite heat, but strong and infrequent movements differ from weak and frequent movements, as well as from frequent ones, alternating with rest, in that they warm the body very much, but dissolve less, if dissolved at all. As for frequent movements, they dissolve a little, but more than they warm up. When each of these types of movement becomes excessive, they cool due to excessive dissolution of the innate heat, and also dry out. If movements are associated with some substance, then sometimes the substance produces an effect that promotes the action of the movement, and sometimes its action weakens the effect of the movement.
So, for example, if the movements are movements made in the laundry craft, then they happen to generate cold and humidity, but if these are movements made in the blacksmith’s craft, then they happen to generate excess heat and dryness. As for rest, it always cools due to the cessation of the rise of heat and locks it in, and also moisturizes, since the excess ceases to be absorbed.