Physical activity level
The physical activity level is a way to express a person's daily physical activity as a number and is used to estimate their total body [energy expenditure|energy expenditure]. In combination with the basal metabolic rate, it can be used to compute the amount of food energy a person needs to consume to maintain a particular lifestyle.
Definition
The physical activity level is defined for a non-pregnant, non-lactating adult as that person's total energy expenditure in a 24-hour period, divided by his or her basal metabolic rate :The level of physical activity can also be estimated based on a list of the physical activities a person performs from day to day. Each activity is connected to a number, the physical activity ratio. The physical activity level is then the time-weighted average of the physical activity ratios.
Examples
The following table shows indicative numbers for the Physical activity level for several lifestyles:| Lifestyle | Example | PAL |
| Extremely inactive | Cerebral palsy patient | <1.40 |
| Sedentary | Office worker getting little or no exercise | 1.40-1.69 |
| Moderately active | Construction worker or person running one hour daily | 1.70-1.99 |
| Vigorously active | Agricultural worker or person swimming two hours daily | 2.00-2.4 |
| Extremely active | Competitive cyclist | >2.40 |