Rest is complete time off with no training at all. For the athlete this is a poor alternative. The body in training is accustomed to a certain level of activity and the more elite the athlete more the body is tuned into training. When the stress of training is taken away completely it can be a negative shock to the body. Complete rest, shutting the body down will result in interference with appetite, poor restless sleep, and a decline in mood state. In addition complete rest makes the return to training more difficult. The analogy would be like taking a high performance race car and parking it in the garage for a period a month and then trying to start the engine and go immediately into a race. It won't work. Rather than restoring the body the athlete who is coming off a day or longer of complete rest will in most cases be flat. Consider the negative reaction and de-training that can occur with a month of rest that is often prescribed between seasons. A big mistake in that situation you are dulling the knife. The viable alternative is active rest. In active rest the “muscles work and the nerves rest.” It is time off from the regular activities of training. “Active” refers to other sports activities or just general physical activity. For example the basketball player could play a game of pickup soccer, a swimmer may go for a bike ride or a distance runner could swim. It is a "break" absence from high stress not absence from activity but still gives the athlete the stimulus that activity provides to keep the engine idling so a complete restart is unnecessary.