Determine energy expenditure for Climbers?

The energy expenditure of 3250 Kcal/ day is reported in climbers to Mt. Everest using doubly labeled water teaching. Out of this, 1610 Kcal/ day were required just for climbing activities. The physical activity level (PAL) calculated using doubly labeled water and expressed as a multiple of BMR in trained subjects during climbing reached 2.0-2.7, which was lower than the upper limit (4.0-5.0) at sea level. In a study by Reynolds et a1 (1999), energy expenditure in 7 climbers to Mt. Everest was in the range of 2675- 7872 Kcal/day. On the basis of data obtained from climbers who rue highly motivated people, generalization of nutrient and energy requirements for the general population is difficult.