BMR (BASAL METABOLIC RATE)
Your basal metabolic rate (BMR) is the number of calories your body uses when it is at rest. BMR accounts for most of your calorie use. Your basal metabolic rate is based on things your body always does such as breathing, breaking down food, and keeping your heart and brain working. Your age, sex, body weight, and level of physical activity affect the basal metabolic rate. Basal metabolic rate increases with the amount of muscle tissue you have, and it reduces with age.
(Source: NIH; Medline Plus, National Library of Medicine 2007)
