Modern life is becoming increasingly sedentary and has been associated with an
increased risk of obesity. Most modern jobs can be carried out with less physical effort
due to technical progress, urbanization, transport and availability of a large range of
domestic electrical appliances resulting in substantial decline in the energy spent in these
activities. Recent studies (Table 11) in different age groups suggest that with the
exception of armed forces and elite athletes, Malaysians are also leading a sedentary
lifestyle (Ismail 2002). Physical activity level (PAL) values express daily energy
expenditure as multiples of BMR.
There is convincing evidence that regular physical activity is protective against unhealthy
weight gain whereas sedentary lifestyles, particularly sedentary occupations and inactive
recreation such as watching television, promote it (WHO 1998).
5.4.1 Definition
The definition of physical activity and physical inactivity (sedentary behaviour) has been
reported in the WHO 1998 Report.
Physical activity is defined as any bodily movement produced by skeletal muscles that
result in a substantial increase over the resting energy expenditure (Bouchard et al. 1994).
It has three main components:
(i) Occupational work - activities undertaken during the course of work
(ii) Household and other chores - activities undertaken as part of day-to-day living
Table 11: Basal metabolic rate (BMR,