Physical activity level is about numerical expression of a person’s daily activities. Physical activity level is determined by a person’s daily total energy expenditure and basal metabolic rate. In order to calculate physical activity level, a person’s total energy expenditure over 24 hour-period has to be divided by his or her basal metabolic rate. Some definitions of physical activity level are more specific. More specific determination of physical activity level involves a person’s total energy expenditure over 24 hour period, to be divided by his or her basal metabolic rate over 24 hour period.
The equation of Physical activity level (PAL) is as follows:
Physical activity level = Total energy expenditure (over 24 hour period)/Basal metabolic rate (over 24 hour period).
Use of Physical Activity Level
Physical activity level and Basal metabolic rate of a person are used in calculation of daily food energy need of the person.
Daily energy requirement (over 24 hour period) = Basal Metabolic Rate * Physical Activity level.
Determining daily need for energy or calorie intake is important. There is need to have a balance between daily calorie intake and daily calorie expenditure. Physical activity level helps calculating need for daily calorie intake. In addition, have a balance between calorie intake, calorie expenditure and control weight. The equation for daily energy requirement does not work for pregnant or lactating adults.
There is another version of calculating food energy requirement or Estimated Average Requirement (EAR). Estimated Average Requirement is determining the amount of energy needed to satisfy a particular proportion or 50% of population.
EAR = PAL * BMR
The difference between two equations is that one is about determining daily energy need for individual person. And the other equation is about using average values to calculate dietary reference values for a particular proportion of people.
Physical Activity Levels
Physical activities performed by an individual within a 24 hour period and the amount of time involved in each activity are taken into consideration to estimate physical activity level. There are 5 levels of physical activities each of which has different values for men and women. Below are the five different physical activities levels.
This level involves minimal activities such as reading, watching TV, playing cards etc.
Activities of housewives, unemployed persons, lab workers, teacher, doctors, shop workers, lawyers, officer workers etc. fall into this level. This level of physical activity involves 16 hours of standing or sitting and eight hours of sleep. 3 out 16 hours has to include light activities such as ping pong, golf, laundry, walking etc. 1 hour has to involve moderate activities such as dancing, tennis, aerobics etc.
Activities of commercial fishermen, soldiers not in active service, building trades, many farm workers, carpentry, electrical and light industry fall into this level. This level does not involve heavy labors. If a person is in office job or driving occupation, he or she has to do exercises for 1.5 to 2 hours to be at moderately active level.
Activities of forestry workers, mineworker, steel worker, soldiers in active service, some agricultural workers, unskilled laborers and full time athletes fall into this level. Intensity of activities of this level is comparable to nine to thirteen hours of running a day.
This level involves heavy labor. Activities of rickshaw pulling, manual digging, construction work, blacksmith, coal mining etc fall into this level. Intensity of activities of this level is comparable to fourteen to seventeen miles a day.
There are values or activity factor for each level of physical activity. Value for men is 0.3 and women is 0.3, at sedentary level. Value for men is 0.6 and women is 0.5, at lightly active level. Value for men is 0.7 and women is 0.6, at moderately active level. Value for men is 1.1 and women is 0.9, at very active level. Value for men is 1.4 and women is 1.2, at extremely active level.
Last update: June 18, 2017 01:44:06 pm