[Swimming for 12 hours leads to no reduction of adipose subcutaneous tissue--a case study]

In a 12-hour swimming event, an athlete with constant body weight lost 1.1 kg of muscle mass and 21 of total body fluids whereas fat mass remained stable. Based both on the urine's specific gravity and haematological parameters, the athlete did not suffer from dehydration. We assume that loss of skeletal muscle mass occurred due to degradation of intramyocellular lipids and muscle glycogen. In order to confirm these results obtained in a case study regarding the decrease of skeletal muscle mass with stable fat mass during prolonged swimming exercise, a larger number of athletes would have to be analyzed.