MEASURES OF PHYSICAL ACTIVITY

Physical activity is the expenditure of energy generated by moving muscles in the body, including incidental activity such as housework or gardening. Exercise is an example of physical activity that is mainly done for the purpose of enhancing or maintaining physical fitness, as well as for enjoyment [7]. There are various ways to measure an individual's physical activity levels, including the frequency, intensity, duration and type of physical activity they undertake.

The National Physical Activity Guidelines for Adults recommend at least a moderate level of physical activity, most days of the week, for a total of 30 minutes or more on each of those days, and with each session lasting 10 minutes or more [8]. Based on these guidelines, people who are sedentary or exercise at low levels will not be achieving the amount of physical activity required to obtain the associated health benefits.


MEETING THE GUIDELINES

In 2007-08, around 62% of adults did not meet the recommended physical activity guidelines, with a higher proportion of women not meeting the guidelines than men (64% and 60% respectively).

The proportion of people who did not meet the guidelines was highest for those aged 75 years and over (76%), while the proportions for remaining age groups were relatively similar, ranging from 56% to 64%.

(a) The National Physical Activity Guidelines for Adults.
(b) Based on exercise undertaken for fitness, recreation or sport in the last week.

Source: National Health Survey, 2007-08


TYPE OF EXERCISE

The type of exercise that people did in the week prior to interview was grouped into four categories: no exercise, walking, moderate and vigorous. Almost 40% of adults in Australia did no exercise in the last week, 44% reported that they walked for fitness, sport or recreation, 31% did some form of moderate exercise and 13% engaged in vigorous exercise.

Women were more likely to walk for exercise than men (46% compared with 41%), while men were more likely to undertake moderate exercise (34% compared with 29%) and vigorous exercise (16% compared with 10%).

Moderate and vigorous exercise were more common among younger age groups, while those in the older age groups were more likely to walk for exercise. Forty per cent of people aged 18-34 years reported moderate exercise and around one in five (21%) reported vigorous exercise. Almost half (48%) of adults aged between 65 and 74 years walked for exercise.


WALKING FOR TRANSPORT

Physical activity not intentionally undertaken for the purpose of fitness, sport or recreation, such as walking for transport, also contributes to the health of an individual. In the week prior to interview, more than half (57%) of people aged 18 years and over walked continuously for transport for at least 10 minutes. While older people tended to walk for exercise, fitness or recreation more often than younger people, walking for transport was more common among the younger age groups. Around two-thirds (66%) of people aged 18-24 years walked for transport, compared with 45% of those aged 75 years and over.


NUMBER OF DAYS EXERCISED

The benefits of regular physical activity, such as boosting the immune system and maintaining a healthy weight, are widely known [9]. Of the people who exercised in the last week, just over one-third (36%) exercised on two or three of the last seven days. Around 18% of people exercised just once in the last week, which was the same proportion as those who exercised every day (Graph 1.2). Slightly more men exercised every day in the last week than women (19% compared with 17%).

(a) Based on exercise undertaken for fitness, recreation or sport in the last week.

Source: National Health Survey, 2007-08


The number of days that people exercised generally increased with age. Around 14% of adults aged 18-24 years did some form of exercise on every day of the last week, compared with 35% of those aged 75 years and over. These results may be due to the large proportion of older people who have retired or work on a part-time basis and can spend more time on their physical fitness and health.

Older people aged 75 years and over were more likely than those aged 18-24 years to walk for exercise every day of the last week (32% and 10% respectively).

This pattern could be seen among both men and women. Men aged 75 years and over were around 4 times more likely to have walked every day in the past week than those aged 18-24 years (33% and 8% respectively). For women, those aged 75 years and over were almost three times more likely than those aged 18-24 years to have walked every day in the past week (30% compared with 11%).


LEVEL OF EXERCISE

Level of exercise was used as an overall measure to indicate the quality of activities undertaken in terms of maintaining heart, lung and muscle fitness. For more information on level of exercise, see Data sources and definitions.

There were more people who were sedentary (40%) than any other exercise level. This was followed by around 32% of adults with low exercise levels, while 22% had moderate exercise levels and 6% reported high exercise levels.

The proportion of people who were sedentary or exercised at low levels increased with age. Around two-thirds (66%) of people aged 18-24 years were sedentary or had low exercise levels, compared with 83% of people aged 75 and over.

In general, women were more likely to be sedentary or exercise at low levels compared with men, with the largest difference existing for adults aged 18-24 years (73% compared with 60%) (Graph 1.3).

(a) Level of exercise undertaken for fitness, recreation or sport in last week.

Source: National Health Survey, 2007-08


TIME SPENT SITTING AT LEISURE

A recent Australian study has found that prolonged periods of sitting may not only be detrimental to people's health but may also counteract the benefits of regular moderate to vigorous physical activity [10]. This is thought to be due to decreases in insulin sensitivity and abnormal processing of glucose that are associated with sitting for lengthy periods without standing up or moving around [11].

In the 2007-08 NHS, adults were asked how much time they spent sitting at leisure; for example, watching television or using a computer. More than three out of four adults spent between two and six hours a day sitting at leisure (78%). In general, men and women spent around the same time sitting at leisure.