Many swimmers experience intense feelings of hunger after completing their laps, often more so than after other equally vigorous cardiovascular workouts. The main reason for an increased feeling of hunger and weight loss after swimming involves the temperature of the water. Swimming in colder water will burn more calories since the body expends calories to keep itself warm as well as to keep swimming.
Depending on your body weight, you can burn anywhere from 250 to more than 400 calories for every half-hour of light intensity swimming, according to the American Council on Exercise. As the intensity of the swim increases, so does the caloric expenditure. A half-hour of vigorous swimming, for example, can burn as many as 600 calories.
A 2005 study conducted by University of Florida researchers and published in the “International Journal of Sport Nutrition and Exercise Metabolism” showed that water temperature affects swimmers’ appetites. Study participants swam for 45 minutes in a 68-degree pool. After swimming, the participants ate 40 percent more than the control group.
Caloric expenditure during swimming is also affected by the type of stroke you swim. You will likely feel hungrier and lose weight after swimming a high-intensity stroke such as front crawl, back crawl or butterfly as opposed to a resting stroke like breaststroke.
Since swimming stimulates appetite, be mindful not to overeat after a swimming session. A 1987 study conducted by University of California researchers and published in the “American Journal of Sports Medicine” studied a group of overweight women following cardiovascular exercise programs in a bid to lose weight. The group that swam lost no weight whatsoever. The pool this group swam in was 73 degrees, which may explain why they ate more – and hence maintained their weight.