The basal metabolic rate is the amount of energy the body needs in complete rest to maintain basic functions such as breathing, heartbeat, body temperature and cell metabolism. For most people it accounts for the largest share of total daily energy expenditure.
The basal metabolic rate depends on body weight, muscle mass, age and sex, among other things. Because muscle tissue uses more energy at rest than fat tissue, people with a higher share of muscle tend to have a slightly higher basal metabolic rate. Various formulas estimate the basal metabolic rate approximately; exact values can only be determined with special measuring equipment.
Relevance for nutrition and sport
Together with the activity-related energy expenditure from movement, the basal metabolic rate forms the basis for calculating total energy needs, which in turn matter for judging a sensible calorie intake. If the basal metabolic rate is underestimated in planning, a planned diet can turn out stricter than intended.
Strength training and a higher share of muscle can raise the basal metabolic rate slightly over the long term, although the effect of individual training sessions is usually overestimated. For a realistic assessment of your own energy needs, including the basal metabolic rate, the guide calculating protein requirements helps. A rough estimate is usually enough for everyday planning; an exact measurement is rarely necessary and is reserved for special questions.