AUSTRALIAN IDLE: PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOUR OF ADULT AUSTRALIANS


INTRODUCTION

Physical activity has many health benefits including helping to prevent heart disease, Type 2 diabetes and some cancers, and improving psychological well being (Endnote 1).

According to the 2011-12 National Health Survey, 63% of adults aged 18 years and over were either overweight or obese, and this rate has increased over time. Along with poor nutrition, the main factors associated with increases in obesity and being overweight are sedentary behaviour and physical inactivity (Endnote 2). With lifestyles becoming increasingly more sedentary, the level of physical inactivity has continued to rise over time (Endnote 3).

The 2011-12 National Nutrition and Physical Activity Survey (NNPAS) explored levels of physical activity. To measure physical activity, the NNPAS collected data on walking for transport, walking for fitness and moderate and vigorous physical activity for fitness, recreation or sport undertaken in the week prior to interview. Respondents' levels of physical activity were categorised as:

• High
• Moderate
• Low, or
• Sedentary

based on the duration and intensity of this physical activity.

For sedentary behaviour, data were collected on sitting at work, sitting for transport and sitting or lying down for other social or leisure activities.

This article commences with a general look at levels of physical activity among the Australian adult population, before focussing on those with sedentary levels of physical activity. The article will explore in detail the characteristics of Australians with sedentary levels of physical activity, how they are spending their sedentary time and how much time they spend being sedentary.

This is one of two articles produced for the November 2013 issue of Perspectives on Sport which uses data from the 2011-12 NNPAS to examine levels of physical activity among adult Australians. The corresponding article, Let's Get Physical - How do Australians Measure Up? examines what proportion of adult Australians meet the National Physical Activity Guidelines, by selected demographic and socio-economic characteristics. 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 4).

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


LEVEL OF PHYSICAL ACTIVITY

When the level of physical activity is considered for all Australian adults, more people reported sedentary levels of physical activity (21% or 3.6 million) than high levels of physical activity (15% or 2.5 million). More than one-quarter (28%) of Australian adults reported moderate levels of physical activity, with over one-third (35%) reporting low levels.

Males and females reported similar rates of sedentary levels of physical activity (21%). However, males reported higher rates of high levels of physical activity (19%, compared with 11% of females) and lower rates of low levels of physical activity (31% compared with 39% of females).

NUMBER ('000s)
	High	Moderate	Low	Sedentary (b)	Not Stated	Total
Males	1 587.3	2 282.6	2 631.6	1 763.8	140.9	8 406.3
Females	962.2	2 436.5	3 331.1	1 843.1	63.0	8 635.9
Persons	2 549.6	4 719.0	5 962.7	3 606.9	203.9	17 042.2
PARTICIPATION RATE (%)
	High	Moderate	Low	Sedentary (b)	Not Stated	Total
Males	18.9	27.2	31.3	21.0	1.7	100.0
Females	11.1	28.2	38.6	21.3	0.7	100.0
Persons	15.0	27.7	35.0	21.2	1.2	100.0

(a) In the week prior to interview.
(b) Includes very low and no exercise.

Source: ABS National Nutrition and Physical Activity Survey, 2011-12


PERSONS WITH SEDENTARY LEVELS OF PHYSICAL ACTIVITY

The focus of this article will now move specifically to those Australian adults who reported sedentary levels of physical activity, and the demographic, socio-economic and geographic characteristics of this group. 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.

Age and Sex

The lowest rate of sedentary levels of physical activity was reported by people aged 18-24 years (11%). Sedentary levels of physical activity generally increased between young adult ages and middle age. Rates of sedentary levels of physical activity then appear to plateau to around age 75, before increasing substantially for the age group 75 and over (42%).

Differences in the sedentary rates of males and females varied by age group. Older males (aged 75 and over) reported lower rates of sedentary levels of physical activity than their female counterparts (35% compared with 47%). Young males (aged 18-24 years) also reported lower rates of sedentary levels compared with females of the same age (10% compared with 13%), however there is not enough evidence to suggest that this difference is statistically significant. Women in the middle age groups (25-34, 35-44, 45-54 and 65-74) generally reported lower rates than males in these age groups, however there is not enough evidence to suggest these differences are statistically significant.



Level of physical activity over time

In previous iterations of the health survey walking for transport was excluded from the information collected for exercise in the week prior to interview. Consequently, to provide a time series comparison, walking for transport was excluded from the 2011-12 figures presented in the graph below.

Sedentary levels of physical activity have increased over time from 34% in 2004-05 to 41% in 2011-12. This increase occurred for both males and females from 2004-05 (33% for males and 35% for females) to 2011-12 (39% for males and 42% for females). Although females reported higher rates of sedentary levels of physical activity than males at the three time periods, there is not enough evidence to suggest that these differences are statistically significant.



Household structure

For most household types there was little variation in the rates of sedentary levels of physical activity for all persons. However, one person with children households (26%), person living alone households (24%) and couple only households (23%) reported higher rates of sedentary levels of physical activity than those in couple with children households (18%).

When examining the rates including sex, some variation can be seen for most household types. It can be seen that females living in single parent households reported higher rates of sedentary levels of physical activity compared with males in single parent households (27% compared with 23%). In couple only households males reported higher rates of sedentary levels of physical activity than females (24% compared with 22%). However there is not enough evidence to suggest that these differences are statistically significant.



Country of birth

Rates of sedentary levels of physical activity were similar for those born in Australia (22%) and those born overseas (20%). However greater disparity is seen when looking at region of birth in more detail. Persons born in Southern and Eastern Europe and North Africa and the Middle East (29% and 28% respectively) reported higher rates of sedentary levels of physical activity than those born in North-East Asia (12%). While it appears that those born in North-East Asia reported lower rates of sedentary levels of physical activity than all other regions, there was not enough evidence to suggest that all of these differences were statistically significant.



Education

There is a general decline in the rates of sedentary levels of physical activity as the level of highest non-school qualification increases. Persons who had no non-school qualification reported higher rates of sedentary levels of physical activity (27%) than those with a Postgraduate Degree (9%). There was some variation when examining level of educational attainment by sex. While it appears that for higher educational attainment (an Advanced Diploma/Diploma or higher), females reported higher rates of sedentary levels of physical activity, there is not enough evidence to suggest that these relationships are statistically significant. It also appears that females with no non-school qualification reported higher rates of sedentary levels of physical activity than their male counterparts (28% compared with 25%), however, again there is not enough evidence to suggest that this relationship was statistically significant.



Socio-economic Disadvantage

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 (Endnote 5). 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.

Rates of sedentary levels of physical activity decline as the level of disadvantage decreases. More than a quarter (28%) of those living in areas of the highest disadvantage reported sedentary levels of physical activity, whilst 14% of those in the least disadvantaged areas reported sedentary levels of physical activity. Rates of sedentary levels of physical activity do not vary by sex.



State and Territory

Similar rates of sedentary levels of physical activity were reported by persons in Queensland (25%), the Northern Territory (24%), Tasmania (23%) and South Australia (23%), compared with a lower rate of sedentary activity in the Australian Capital Territory (17%).




TYPE OF ACTIVITY PARTICIPATED IN

Around 9 in 10 adults with sedentary levels of physical activity reported watching TV and sitting for transport. Over half (55%) of adults with sedentary levels of physical activity reported sitting or lying down to use the computer or the Internet and almost half (46%) spent time sitting at work.




TIME SPENT PARTICIPATING

An analysis of average time spent on sedentary activities revealed that persons with sedentary levels of physical activity on average spent 30.9 hours in the week prior to interview being sedentary for leisure. When including sedentary time spent at work, persons with sedentary levels of physical activity on average spent 38.4 hours per week being sedentary.

Persons with sedentary levels of physical activity spent, on average, 16 hours in the week prior to interview watching television or videos and 7.6 hours in the week sitting at work.




SUMMARY

This article has shown that the proportion of the population with sedentary levels of physical activity has increased over time from 2004-5 to 2011-12. Variations in rates of sedentary levels of physical activity can be observed across geographic and demographic groups. For some variables, such as household structure and sex, there is not enough evidence to suggest that they have an influence on rates of sedentary levels of physical activity.

Rates of sedentary levels of physical activity appear to be most affected by age, generally increasing between young adult ages and middle age before plateauing to around age 75, after which the rate increases again.

Level of non-school qualification also appears to be an influencing factor with rates of sedentary levels of physical activity being lower for persons with a higher level of non-school qualification compared with those with a lower level of non-school qualification.

In addition, while there was some variation in rates of sedentary levels of physical activity by state, more observable differences in rates could be seen when examining the Index of Relative Socio-economic Disadvantage.

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.

The most common types of sedentary activities participated in by those with sedentary levels of physical activity was watching television or videos and sitting for transport.


ENDNOTES

1. The Department of Health, Physical Activity, Accessed 14 August 2013 <http://www.health.gov.au/internet/main/publishing.nsf/Content/health-pubhlth-strateg-active-index.htm>
2. Australian National Preventive Health Agency, State of Preventative Health, 2013, Accessed 22 August 2013 < http://www.anpha.gov.au/internet/anpha/publishing.nsf/Content/state-of-prev-health-2013/$FILE/ANPHA%2041087%20State%20of%20Preventative%20Health_acc_pdf.pdf>
3. World Health Organisation, Obesity and Overweight Fact Sheet, Accessed 15 August 2013 <http://www.who.int/mediacentre/factsheets/fs311/en/>
4. Australian Bureau of Statistics, 2013, Australian Health Survey: Users' Guide, 2011-13, cat. no. 4363.0.55.001, ABS, Canberra.
5. Australian Bureau of Statistics, 2013, Census of Population and Housing: Socio-Economic Indexes for Areas (SEIFA), Australia, 2011, cat. no. 2033.0.55.001, ABS, Canberra.