Activity energy expenditure is the amount of energy the body uses through physical activity in addition to the basal metabolic rate. This includes both targeted training and everyday movement such as walking, climbing stairs or household tasks, which together can make up a considerable share of activity energy expenditure.
How high activity energy expenditure is depends strongly on the type, duration and intensity of the activity and on body weight. Intense endurance sessions or strength training raise energy expenditure during and partly after the exertion, while sedentary activities contribute hardly anything to activity energy expenditure.
Relevance for nutrition and sport
Together with the basal metabolic rate, activity energy expenditure makes up total energy expenditure, which serves as the basis for estimating calorie needs. If activity energy expenditure is overestimated, a planned calorie intake can end up higher than actually needed, which makes weight change harder.
For physically active people, it is worth making a realistic rather than overly optimistic estimate of their own activity energy expenditure, for example using activity levels or training logs. The guide calculating protein requirements shows how total energy needs, including activity energy expenditure, can be calculated approximately. Everyday movement outside targeted training also contributes noticeably to total activity energy expenditure, which is often underestimated when planning nutrition, even though it adds up over the week.