LET'S GET PHYSICAL: HOW DO ADULT AUSTRALIANS MEASURE UP?


INTRODUCTION

In March 1997, the National Health and Medical Research Council (NHMRC) published a strategic plan, Acting on Australia's weight, based on the findings of the NHMRC Working Party on the Prevention of Obesity. The goals of the plan were to prevent further weight gain in overweight adults, eventually reduce the proportion of the adult population that were overweight or obese and ensure the healthy growth of children (Endnote 1).

One of the key recommendations of the plan was to develop guidelines for physical activity, recognising the importance of incidental activity and low to moderate intensity activity for all Australians. In June 1997, the Australian Government commissioned the University of Western Australia and the Centre for Health Promotion and Research Sydney to develop a series of National Physical Activity Guidelines. These guidelines, which refer to the minimum levels of physical activity required for good health, still remain important benchmarks against which physical activity (and, by extension, overall health and well-being) is measured in Australia.

There are separate guidelines and recommendations for Australian adults (18 years and over) and children.

This article will examine what proportion of adult Australians meet the National Physical Activity Guidelines, by selected demographic and socio-economic variables. Data has been derived from the 2011-12 ABS National Nutrition and Physical Activity Survey (NNPAS).

This is one of two articles produced for the November 2013 issue of Perspectives on Sport which uses data from the NNPAS to examine levels of physical activity among adult Australians. The corresponding article, Australian Idle: Physical Activity and Sedentary Behaviour of Adult Australians, focuses on the characteristics of those people with sedentary levels of physical activity, how they are spending their sedentary time and how much time they spend being sedentary. Data presented in the two articles are intended to be complementary, however comparisons between the populations presented in the two articles should not be made as different data items are used in analysis. More information about the populations presented can be found in the Adult Physical Activity Survey section of the Australian Health Survey: Users' Guide, 2011-13 (Endnote 2).

For Australian adults, the National Physical Activity Guidelines recommend at least 30 minutes of moderate intensity physical activity on most (preferably all) days. In the NNPAS, this recommendation has been translated to the following measure, considered to correlate to good health outcomes:

• 150 minutes of physical activity (including walking for fitness and transport, and 'moderate' and 'vigorous intensity' activity) over five or more separate sessions per week. This is classified in the survey as 'sufficiently active for health'.

`Vigorous intensity' physical activity is defined as activity undertaken for fitness, recreation or sport that caused a large increase in the respondent's heart rate or breathing. 'Moderate intensity' physical activity is defined as activity that caused a moderate increase in heart rate/breathing, and was not already reported as vigorous physical activity. Moderate and vigorous activity excludes household chores, walking, gardening and yard work.

This article classifies adult Australians as 'inactive', 'insufficiently active' or 'sufficiently active for health', based on the time, intensity and frequency of physical activity undertaken in the week prior to interview.

Note that all data comparisons in this article should be considered significantly different unless otherwise indicated.

Further information about the National Nutrition and Physical Activity Survey and the National Physical Activity Guidelines can be found in the Australian Health Survey: Users' Guide, 2011-13 (cat. no. 4363.0.55.001).


SUFFICIENTLY ACTIVE FOR HEALTH

Overall, what proportion of the Australian population meets the National Physical Activity Guidelines?

In 2011-12, 43% of adult Australians met the sufficiently active threshold (i.e. they undertook at least 150 minutes of physical activity over five or more separate sessions in the week prior to interview). A higher proportion of males (45%) were classed as sufficiently active for health compared with females (41%).

Around 20% of males and females were classed as inactive (i.e. they undertook no physical activity, including walking for transport and fitness, and moderate and vigorous activity, in the week prior to interview).

Approximately 36% of adult Australians were classed as insufficiently active (i.e. they are not completely inactive but they failed to meet the requirement of at least 150 minutes of physical activity over five or more separate sessions in the week prior to interview). A higher proportion of females were classed as insufficiently active compared with males (37% compared with 34%).



The focus of this article will now shift specifically to those adult Australians who were classed as sufficiently active for health, examining variations across geographic, demographic and socio-economic groups.


GEOGRAPHICAL VARIATIONS

States and Territories

The Australian Capital Territory had the highest proportion of its population (almost 50%) classed as sufficiently active for health. The Northern Territory recorded the lowest proportion (37%).

The proportion of males classed as sufficiently active in the Northern Territory (35%) was observably lower than the rates for males in other states and territories, although with the exception of New South Wales, Western Australia and the Australian Capital Territory, there is not enough evidence to suggest that these differences are statistically significant.

The proportion of females classed as sufficiently active in the Australian Capital Territory (47%) was considerably higher compared with females in Queensland and South Australia (both 38%).




DEMOGRAPHIC VARIATIONS

Age and Sex

To what extent does age affect the likelihood of being sufficiently active for health?

In 2011-12, Australians aged 18-24 years were more likely to meet the national guidelines than any other age group (53%). The proportion of the population who met these guidelines generally declined with age, with approximately one in four Australians aged 75 years or over being classed as sufficiently active.

Compared with females, a greater proportion of males in the 18-24 age group (59% compared with 48%) and those aged 75 years and over (32% compared with 20%) were classed as sufficiently active for health. There is not enough evidence to suggest that the differences between males and females are statistically significant in the other age groups.



Household Structure

Can levels of physical activity vary across different types of households? For example, are people who live alone more or less likely to meet the national guidelines compared with couples, couples with children, or single parents?

Around 44% of Australians who live alone were classified as sufficiently active. This was similar to the proportion of households consisting of couples only (42%) and those with couples and children (43%).

Although just 39% of males in single parent households were classed as sufficiently active (compared with 47% of males with partners and children, and 46% of males living alone) there was not enough evidence to suggest that these differences are statistically significant.

For females, 43% of those living alone and those living with partners only were classed as sufficiently active for health. Compared with females with partners and children, a slightly higher proportion of females in single parent households were sufficiently active (41% compared with 39%), but there was not enough evidence to suggest that these differences are statistically significant.

In summary, household structure does not seem to be a major influence on a person's likelihood of meeting the national guidelines.




SOCIO-ECONOMIC VARIATIONS

In this section of the article a series of inter-related variables are discussed, including income, socio-economic disadvantage, education, labour force status and occupation. Throughout this section, it should be noted that age may also be a contributing influence, however an age standardisation process has not been conducted as part of the analysis.

Equivalised Household Income

Are people living in lower income households less likely to meet the National Physical Activity Guidelines?

Equivalising adjusts actual income to take into account the different needs of households of different sizes and compositions, so 'equivalised household income' can be seen as an indicator of the economic resources available to each member of the household. It reflects the requirement of a larger household to have a higher level of income to achieve the same standard of living as a smaller household.

For the purpose of this analysis, Australians have been grouped into one of five categories, according to their equivalised household income, ranging from the lowest quintile (representing the lowest 20% of households) to the highest quintile (comprising the top 20% of households).

In 2011-12, just over one in three Australians (35%) living in the lowest income households were classed as sufficiently active for health. The proportion of adult Australians meeting the national physical guidelines generally increased with each successive quintile of households, so that in the highest income households 57% of people were classed as sufficiently active for health.



Socio-economic Advantage and Disadvantage

In addition to household income, an individual's level of physical activity may also be influenced by their socio-economic status. There is a clear relationship between lower socio-economic status and reduced participation in physical activity, which may be due to many factors, including limited financial resources, greater child-minding responsibilities, higher levels of disability, higher levels of psychological distress, or long hours in manual work, all of which can affect people's capacity for participation (Endnote 3).

The Index of Relative Socio-economic Disadvantage (IRSD) summarises information about the economic and social conditions of people and households within an area, including only measures of relative disadvantage. A low score indicates an area of relatively greater disadvantage in general. For example, an area could have a low score if there are many households with low incomes, many people with no qualifications or many people in low skill occupations. A high score indicates an area with a relative lack of disadvantage in general. For example, an area could have a high score if there are few households with low incomes, few people with no qualifications, and few people in low skilled occupations.

To what extent are people living in lower socio-economic areas less likely to meet the national guidelines for physical activity?

Of those Australians living in the areas of greatest disadvantage in 2011-12, 34% were classed as sufficiently active. The proportion of people classed as sufficiently active increased with each successive quintile. Of those people living in the areas of lowest disadvantage, 52% were classed as sufficiently active.



Education

Research has demonstrated that higher education levels can be associated with increased physical activity (Endnote 4). People with higher levels of education may be more informed about the health consequences of lifestyle behaviours, leading them to undertake more frequent and intense physical activity.

How do people with a higher education or tertiary qualifications compare with those who hold no non-school qualifications in terms of physical activity levels?

Overall, the proportion of adult Australians classed as sufficiently active were higher for those with a Postgraduate degree (60%), Graduate Diploma/Graduate Certificate (57%) or Bachelor degree (55%) than those holding Advanced Diplomas/Diplomas (46%), Certificates (38%) or those who had no non-school qualifications (37%).

Compared with females (34%), a higher proportion of males with no non-school qualification (40%) were classed as sufficiently active.

Compared with females, higher proportions of males with Graduate Diplomas/Graduate Certificates, Bachelor degrees and Advanced Diplomas/Diplomas were classed as sufficiently active, but there was not enough evidence to suggest that these differences are statistically significant.



Labour Force Status

Are employed people more likely to meet the National Physical Activity Guidelines than unemployed Australians?

There is no statistical evidence to suggest this is the case. In 2011-12 a similar proportion of employed Australians (45%) and unemployed Australians (48%) were classed as sufficiently active.

However, both employed and unemployed people were more likely to meet the national guidelines than those not in the labour force (i.e. retirees, those who no longer work, do not intend to work in the future, are permanently unable to work, or have never worked). Around 37% of Australians not in the labour force were classed as sufficiently active for health.

Of those not in the labour force a higher proportion of males (41%) than females (35%) were classed sufficiently active for health.



Occupation

Are people in certain occupation groups more or less likely to be sufficiently active than others?

Compared with other occupation groups, a higher proportion of Professionals were classed as sufficiently active (59%). This compared with 47% of Community and Personal Service Workers, 46% of Clerical and Administrative Workers, 45% of Managers and 45% of Sales Workers.

Those occupation groups with the lowest proportion of workers classed as sufficiently active included Machinery Operators and Drivers (32%), Technicians and Trade Workers (35%) and Labourers (36%).




SELF ASSESSED HEALTH STATUS

Respondents in the National Nutrition and Physical Activity Survey were asked to rate their overall health (either excellent, very good, good, fair or poor). Although this is clearly a subjective question, and perceptions may be influenced by any number of factors unrelated to health (or may reflect momentary or short-term feelings or circumstances), self-assessed health has been shown to be a good indication of a person's health at the population level (Endnote 5).

Data for 2011-12 show that Australians who reported their health as excellent were twice as likely to meet the national guidelines than those who reported their health as poor. Around 57% of people who reported excellent health were classed as sufficiently active. This compared with just 26% of those who reported their health as poor.

In general, as the quality of self-assessed health reduced, so did the proportion of the population who were classed as sufficiently active.

Compared with females (34%), a higher proportion of males (45%), who reported their health as good, were classed as sufficiently active.




SUMMARY

The National Physical Activity Guidelines recommend at least 30 minutes of moderate intensity physical activity on most (preferably all) days as a minimum requirement for good health.

In the NNPAS this recommendation translates to 150 minutes of physical activity (including walking for fitness and transport, and moderate and vigorous intensity activity) over five or more separate sessions per week to be classified as sufficiently active for health.

In 2011-12, 43% of Australians were classed as sufficiently active for health, however, this article has shown that the proportion of the population meeting the national guidelines varied across geographic, demographic and socio-economic groups.

For some variables, such as household structure and labour force status, there is little statistical evidence to suggest they have a major influence on a person's ability to meet the national guidelines. However, other variables (such as age, household income, education, occupation and socio-economic status), do seem to have an influence.

As noted earlier, variables such as income, education and socio-economic status can also be influenced by age. Further analyses involving age standardisation would be required to further understand these relationships.

Finally, there appears to be a relationship between people's self-assessed health status and their level of physical activity. Australians who reported their health as excellent were twice as likely to be classed as sufficiently active than those who reported their health as poor.


ENDNOTES

1. National Health and Medical Research Council, 1999, Physical Activity Guidelines for Australians: Scientific Background Report, Accessed 29 October 2013 < http://www.health.gov.au/internet/main/publishing.nsf/Content/F1AE72BE17E87B06CA257BF0001958E6/$File/scientific.pdf >

2. Australian Bureau of Statistics, 2013, Australian Health Survey: Users' Guide, 2011-13 (cat. no. 4363.0.55.001)

3. Australian Bureau of Statistics, 2011, Physical Activity in Australia: A Snapshot, 2007-08 (cat. no. 4835.0.55.001)

4. Cleland Verity J, Ball K, Magnussen C, Dwyer T and Venn A, 2009, 'Socio-economic position and the tracking of physical activity and cardiorespiratory fitness from childhood to adulthood', American Journal of Epidemiology 170.9, p. 1067-1077. Accessed 29 October 2013 < http://aje.oxfordjournals.org/content/170/9/1069.full.pdf+html >

5. Australian Bureau of Statistics, 2012, Australian Health Survey: First Results, 2011-13 (cat. no. 4363.0.55.001)