Thermogenic effect of food in physically well-trained elderly men.

Basal metabolic rate (BMR) and the thermogenic effect of food (TEF) after a liquid mixed meal of 2092 kJ (500 kcal) were examined in physically well-trained, elderly men in comparison with sedentary weight- and age-matched controls. BMR tended to be higher and TEF was significantly higher in the physically well-trained men than in the controls. No certain differences were found in plasma thyroid hormones or catecholamines. BMR correlated with whole body potassium while TEF did not. The tendency to elevated BMR in the well-trained men might therefore be due to their greater muscle mass. The elevated TEF, however, probably has other causes and might be associated with the elevated catecholamine sensitivity associated with the physically trained condition.