Marty has enhanced his cardiovascular fitness, a laudable goal. In addition, after a period of training, muscle cells worked on a regular basis will make more mitochondria. Since mitochondria are the sites of aerobic metabolism, this means that more ATP can be generated. ATP is a necessary component for muscle action.
Many wrestlers and other athletes lose weight quickly by losing large amounts of water, usually by sweating. By doing so, an athlete can compete in a lower weight class and thus gain an advantage over an opponent. However, losing weight this way can significantly impede performance. Over time, repeated dehydration episodes can lead to serious complications, such as kidney failure. Athletes also risk developing heat stress during the event.
The loss of water before a competition is the quick method of losing weight. But, if an athlete is serious about his or her sport, a gradual change in diet to create the best possible weight/muscle composition should be the goal.
