[Energy metabolism in long-term endurance sports: a case study].

During the Swiss Citypower Gigathlon 2002, we determined energy turnover in one athlete. The average intake of calories was at 6500 calories per day and a deficit of 3500 calories per day resulted. This was due to the energy expenditure of about 10,000 calories per day. We concluded that it is extremely difficult or rather impossible to cover the total energy expenditure by nutrition during extreme events.