The Scottish Health Survey 2011 - volume 2: children

4 Physical Activity

Tessa Hill

SUMMARY

• In 1998, 65% of children aged 2-15 were physically active at the recommended level (excluding school-based activity, which was not measured prior to 2008). This increased to 69% in 2003, but has been 64%-65% since 2008.
• In 2011, 73% of children (76% of boys and 70% of girls) met the physical activity recommendations including school-based activity. Although there was little change between 2008 and 2011 in this measure for boys, the proportion of girls meeting the recommendations increased from 64% in 2008.
• Seven in ten children aged 2-4 were active at the recommended level (including school based activity) in 2011; this increased to 80%-81% for children aged 5-10, and then declined to 75% at age 11-12 and further to 59% of those aged 13-15. This decline with age was particularly apparent in girls (48% of girls aged 13-15 met the recommendations compared with 69% of boys).
• Activity levels for girls varied significantly by socio-economic classification. Girls in lower supervisory and technical households stood out as the most active (77% compared with 67%-69% for those living in other household types).
• There was no significant relationship between household income and meeting recommended child physical activity levels.
• Area deprivation was significantly associated with physical activity levels for boys, but not for girls: 81% of boys in the least deprived quintile and 77% in the second most deprived quintile met the recommendations, while the equivalent figure for the remaining groups ranged from 72%-74%.
• Fruit and vegetable consumption was significantly associated with meeting the physical activity recommendations: 65% of children who ate no portions of fruit and vegetables in the previous day met the recommendations. This increased to 79% for children who ate five or more portions.
• Children were more likely to meet the physical activity recommendations if their mothers did so: 80% of boys and 71% of girls whose mothers met the adult recommendations met the recommendations themselves. Children's activity levels were not associated with the activity levels of their father.

4.1 INTRODUCTION

A growing body of evidence suggests that being physically active in childhood has numerous short and longer-term benefits for children's health and development.^[1] The 2011 UK Chief Medical Officers' report, which outlined updated physical activity recommendations for the population, cited positive links between high activity levels and the development of early motor skills and bone strength, the prevention of overweight/obesity, and a reduced incidence of metabolic risk factors as well as mental health problems.^[2] For older children, it appears that physical activity exerts a dose-response relationship whereby the higher the level of activity, the greater the health benefits derived. There is also evidence that the activity habits established in childhood track into adulthood, which suggests that long-term initiatives designed to increase activity levels in the adult population need to take account of children's early experiences. In addition, sedentary activity (such as periods sitting in front of TV or computer screens) has been shown to be independently associated with negative health outcomes, once activity levels have been taken into account.^[2]

The introductions to the physical activity chapters in the three previous Scottish Health Survey (SHeS) reports^[3],[4],[5] provided a comprehensive overview of the recent policy context in this area. They outlined a number of actions being taken by the Government and NHS Scotland to promote physical activity as part of a healthy lifestyle, and initiatives designed to help children increase their activity levels. These included:

• The 2003 Physical Activity Taskforce publication Let's Make Scotland More Active: A strategy for physical activity^[6] and its five year review, conducted in 2008.^[7]
• The Scottish Government's 2008 action plan Healthy Eating, Active Living: An action plan to improve diet, increase physical activity and tackle obesity (2008-2011).^[8]
• The Scottish Government's Route Map for tackling obesity and the associated Obesity Route Map Action Plan, published in 2011.^[9] The Scottish Health Survey's measures of the proportion of children who meet the physical activity recommendations, and the time spent in front of a screen, are being used to monitor progress towards the Plan's intermediate-term goal to increase energy expenditure.^[10]
• The opportunities presented by the 2012 Olympics and 2014 Commonwealth Games to help accelerate progress towards making Scotland more active.
• The Curriculum for Excellence,^[11] adopted in schools from August 2010, which sets out a framework for children and young people (aged 3-18) to experience, on a regular basis, a wide range of purposeful, challenging, progressive and enjoyable physical activities in addition to the required 2 hours of PE.
• The Active Schools^[12] programme which is designed to encourage young people to be involved in physical activity and sporting opportunities outwith PE lessons.

Children are recommended to accumulate at least 60 minutes of moderate activity on every day of the week, which can be accumulated in shorter bouts of as little as 10 minutes. Allied to the above initiatives, the following physical activity target for children is monitored by SHeS:

80% of children aged 16 and under should be meeting the current recommended levels of physical activity by the year 2022

The percentage of children aged 5-15 meeting the recommended level of activity is also one of the new National Mental Health Indicators for children and young people in Scotland.^[13] It is included as part of the individual contextual domain as a measure of healthy living.

Over and above this, additional support has been provided to ensure all primary schools deliver 2 hours of Physical Education (PE) per week and all S1-S4 pupils receive 2 periods of PE. The Healthy Living Survey (published on the 25^th June 2012) showed that 84% of primary schools and 92% of secondary schools were providing two hours of PE per week.^[14]

Children's physical activity is not, of course, confined solely to organised sports or school lessons. Initiatives have also focused on encouraging walking or cycling to school, while, for younger children in particular, funds have been provided to help support active play, for example through the Early Years Early Action Fund.^[15]

The 2010 SHeS Report^[5] outlined the more detailed recommendations for children's physical activity published jointly in July 2011 by the UK's four Chief Medical Officers.^[2] The new UK guidelines for children are tailored to two specific age groups:

• Children under 5
  • Babies should be encouraged to be active from birth (through floor-based play or water activities).
  • Pre-school children who can walk unaided should be active for at least 180 minutes a day.
  • Extended periods of sedentary activities (such as sitting in buggies or watching television) should be limited.
• Children and young people aged 5-18
  • Should engage in moderate to vigorous activity for at least 60 minutes and up to several hours every day.
  • Vigorous activities, including those that strengthen muscles and bones, should be carried out on at least 3 days a week.
  • Extended periods of sedentary activities should be limited.

In line with these new recommendations, from 2012, SHeS includes more questions about children's sedentary activity (since 2003 a question has been asked about hours spent in front of a screen, and from 2012 other sedentary activities such as reading will also be covered). Measuring the intensity level of activity in children, and its muscle strengthening potential, is very difficult. To do this would have required a major revision to the questionnaire and a consequential loss of time series data. It was therefore decided that, for the time being at least, the child physical activity questionnaire would not be adapted to enable monitoring of the more detailed recommendations.

This chapter updates the trends presented in the three previous SHeS Reports for child physical activity levels.^[3],[4],[5] It uses two summary measures based on all types of activities reported by participants (see below for further details). Activity levels are presented by three socio-economic measures: the National Statistics Socio-economic Classification (NS-SEC), household income, and the Scottish Index of Multiple Deprivation (SIMD). To explore the extent to which children share more than one unhealthy risk factor (low activity and low consumption), the association between activity levels and fruit and vegetable consumption is presented. Finally, the chapter takes advantage of the fact that information about activity is collected from all household members to look at the association between parents' and children's activity levels.

4.2 METHODS

4.2.1 The child physical activity questionnaire

The questions on child physical activity included in the 1998, 2003, and 2008-11 questionnaires were based on the 1997 Health Survey for England (HSE) children's physical activity module. The questions covered:

• Sports and exercise
• Active play
• Walking, and
• Housework or gardening.

Questions about time spent on housework or gardening were only asked for children aged 8 and over. Prior to 2008, SHeS did not include sport and exercise, active play and walking undertaken as part of school lessons, although activities undertaken on school premises but not as part of lessons (for example, play or sport at lunchtime or at after-school clubs) were included. However, from 2008 onwards, an additional set of questions was added to the questionnaire specifically asking about 'walking, sports, exercise or other active things' undertaken as part of school lessons.

4.2.2 Child physical activity definitions

Types of activity covered

Further details of what was collected in relation to each activity type are as follows:

Walking

Information was collected about walks of at least 5 minutes duration. Participants were asked on how many days in the last week the child had done walks of at least this length, and how long in total they spent walking on each of those days. Children aged 13-15 were asked about their usual walking pace using the same options as in the adult questionnaire (see above for a description of these).

Housework or gardening (children aged 8 and over only)

For children aged 8 and over, participants were asked about any 'housework or gardening that involved pulling or pushing, like hoovering, cleaning a car, mowing grass or sweeping up leaves'. Only housework or gardening lasting at least 15 minutes was included. Participants were asked on how many days in the last week the child had done such activities, and how long they spent doing this on each day.

Sports and exercise

This category was intended to cover structured or organised sporting activities, and included things like swimming, football, gymnastics and dance lessons. The interview recorded whether the child had participated in any sport and exercise in the last week, on how many week and weekend days they had participated, the total time spent on sport and exercise at the weekend, and the total time on each weekday. There was no lower time limit for inclusion.

Active play

This category covered less structured activities, like riding a bike, kicking a ball around, running about, playing active games or jumping around. The questionnaire asked whether the child had taken part in this kind of 'active play' in the last week, and then, as for sports and exercise, how many week and weekend days they had participated, the total time spent on active play at the weekend, and the total duration each weekday.

School-based activities

Since 2008 the questionnaire has also asked participants about any active things that children who were at school did as part of lessons. They were asked how many days in the last week they did these kinds of activities in lessons, and how long they spent doing them.

Intensity

It is more complicated to assess the intensity of children's activities than is the case with adults. The child physical activity questions do not therefore collect any information on intensity (with the exception of asking those aged 13-15 about their walking pace). For the purposes of calculating physical activity levels, it is assumed that all reported activities were of at least moderate intensity.

The data on the different activities described above has been summarised into an overall measure of child physical activity, which takes into account both the average time spent participating in physical activity and the number of active days in the last week. Child physical activity levels were assigned to one of three categories:

• Meets recommendations - active for 60 minutes on 7 days in the last week (meeting the recommended level of activity for children and young people)
• Some activity - active for 30-59 minutes on 7 days in the last week
• Low activity - active on fewer than 7 days in the last week or for less than 30 minutes a day.

4.3 SUMMARY PHYSICAL ACTIVITY LEVELS

4.3.1 Trends in the proportion of children meeting physical activity recommendations (excluding school-based activities) since 1998

In 2011, 65% of children met the recommendations when activity at school was excluded. This figure was the same in 2010 and has been either 64% or 65% in all other years in the 1998-2010 period apart from a peak of 69% in 2003. Over two-thirds (69%) of boys met the recommendations in 2011. This was significantly lower than the 2003 figure of 74% but similar to all other years which ranged between 68%-72%. The proportion of girls meeting the recommendations has varied more from year to year, fluctuating between 56% and 63%, but with no obvious pattern. In 2011, 62% of girls met the recommendations, the same as was reported in 2010.

The sample sizes are not large enough to compare individual age groups across the years. For example, although the proportion of boys aged 11-12 meeting the target increased by 11 percentage points between 2010 and 2011 (from 60% to 71%), it is likely that this reflects sampling variation rather than real increases in the population. The 11-12 age group is particularly prone to this as it is the smallest sub-group presented in the table (all other sub-groups are based on pooling three chronological years rather than two).
Table 4.1

4.3.2 Children's activity levels (excluding school-based activities), 2011, by age and sex

As in all previous years, in 2011, boys were more likely than girls to meet the physical activity recommendations (excluding school-based activities) (69% compared with 62%).

Up until the age of 8-10, the proportion of children meeting the target varied little by age (ranging between 70% and 72%). It dropped to 64% for those aged 11-12 and to 50% for the oldest age group (13-15 year olds). The main difference between the genders was the point at which the proportion meeting the recommendation began to decline. For boys, levels were largely similar up until aged 13-15 when they dropped to 59%. For girls however, the proportion meeting the target began to drop at age 11-12 (56%) and then reduced further to 41% for those aged 13-15.
Table 4.1

4.3.3 Trends in the proportion of children meeting physical activity recommendations (including school-based activities) since 2008

Since 2008, the survey has measured school-based physical activities. When combined with all other activities, this is a better measure of children's adherence to the physical activity recommendations as activities at school and beyond count towards this. As might be expected, when physical activity undertaken at school is factored in, the proportion meeting the activity targets is higher. In 2011, 73% of children aged 2-15 met the physical activity recommendations, compared with 65% when activity at school was excluded from the measure. As shown in Table 4.2, 72% of children met the targets in 2010 and 71% in both 2008 and 2009. Since 2008, the proportion of boys meeting the recommendations has been stable (75%-77%). The figure for girls increased from 64% in 2008 to 70% in 2010, and remained at this level in 2011. This stability in the figure for girls in the last two years' might signal an upward trend; future years will be able to confirm this.

As noted in Section 4.3.1, the sample sizes for the individual age groups are too small to allow robust conclusions about apparent changes over time to be made. For example, the large differences between years evident among boys aged 2-4, and girls aged 11-12 and 13-15, should not be over-interpreted.
Table 4.2

4.3.4 Children's activity levels (including school-based activities), 2011, by age and sex

As was the case when school based-activities were excluded, boys were more likely than girls to meet the physical activity recommendations in 2011 (76% versus 70%). The pattern by age was similar to that described in Section 4.3.2. Participation rates began to decline at age 11-12 for girls and at age 13-15 for boys.

As would be expected, the proportion of children aged 2-4 meeting the recommendations (70%) was unaffected by the inclusion of school-based activity whereas the figures for school-aged children increased by between 9-11 percentage points. Increases were seen among both sexes and across all age groups.
Table 4.2

4.4 PHYSICAL ACTIVITY BY SOCIO-DEMOGRAPHIC FACTORS

4.4.1 Introduction

Tables 4.3 to 4.5 present children's activity levels by socio-economic classification (NS-SEC of the household reference person), equivalised household income and the Scottish Index of Multiple Deprivation (SIMD) (descriptions of each of these measures are available in the Glossary at the end of this volume). These tables use data from the 2008-2011 survey years combined.

4.4.2 Socio-economic classification (NS-SEC)

For boys, there was no significant association between NS-SEC and whether they were active for at least 60 minutes on every day of the last week. However, the association was significant for girls. Girls living in lower supervisory and technical households stood out as the most active: 77% met the recommendations, compared with 67%-69% in all other types of household. This pattern was also evident when the 2008/2009 figures were analysed, though it is unclear why this group has higher activity levels.
Table 4.3

4.4.3 Equivalised household income

Equivalised income was not significantly associated with meeting the recommendations, though the decrease in girls' activity levels as income declined was close to being significant. The proportions of girls in the three highest household income quintiles meeting the target were 71%-72% before dropping slightly to 67% in the fourth and 64% in the lowest income quintile. Table 4.4

4.4.4 Scottish Index of Multiple Deprivation (SIMD)

Two measures of SIMD are being used throughout this report. The first, which uses quintiles, enables comparisons to be drawn between the most and least deprived 20% areas and the intermediate quintiles. The second compares the most deprived 15% of areas with the rest of Scotland (described in the tables as the "85% least deprived areas").

There was a significant association between SIMD and activity among boys, but not girls. However, the pattern was not linear: 81% of boys in the least deprived quintile, and 77% in the second most deprived quintile, met the recommendations, while for boys in the remaining three groups, the figure ranged from 72%-74%. There were no significant differences in the proportion of boys or girls meeting the physical activity recommendations between those living in the 15% most deprived areas of Scotland and the rest of the country.
Table 4.5

4.5 PHYSICAL ACTIVITY BY FRUIT AND VEGETABLE CONSUMPTION, 2008-2011 COMBINED

Table 4.6 and Figure 4A show how activity levels varied by fruit and vegetable consumption for children in 2008-2011. Eating more portions of fruit and vegetables was significantly associated with an increased likelihood of meeting the physical activity recommendations, although the relationships were not strictly linear. Although these findings illustrate an association between the two activities, they do not, of course, imply a causal link. However, it is evident that risk factors for poor health appear to cluster in children in a similar manner to that found in the analysis of multiple risk factors among adults presented in the 2010 SHeS report.^[16]

The pattern by fruit and vegetable consumption is illustrated in Figure 4A. As the number of portions of fruit and vegetables consumed on the previous day increased, so too did the likelihood of children meeting the activity recommendations. However, the patterns were not strictly linear. 65% of children who ate no portions, and 63% of those who ate less than one portion (but more than none), met the recommendations. This then steadily increased to 79% for children who ate five or more portions. There were some differences in this pattern between boys and girls at the lower end of the fruit and vegetable scale. For example, among boys, those who ate less than one portion (but more than none) were the least likely to meet the recommendations (66% compared with 73%-74% who ate none, or one to fewer than three portions). However, the group that ate less than one portion was the smallest in the population overall so the estimate will be subject to a wide confidence interval. This figure then rose gradually as fruit and vegetable consumption increased, to 76% for those eating three portions, 79% for those eating four and 84% for those eating five or more.

The proportion of boys in the low activity category was highest among those eating less than one portion or no fruit or vegetables (13%). This decreased as fruit and vegetable consumption increased and just 5% of those who ate five or more portions a day were in the low activity group. Girls who ate no fruit or vegetables were the least likely group to meet the recommendations with only 55% doing so. This figure increased to 59% for those eating less than one portion and 64% for those eating one portion a day. The proportion then fluctuated between 68%-72% of girls eating between two and four portions a day before rising to 74% for those eating five portions or more. Just over a fifth (22%) of girls who ate no fruit or vegetables were also in the low activity category, and this decreased to 10% of those eating four portions or more.
Figure 4A, Table 4.6

Figure 4A
% of children who met the physical activity recommendations by fruit and vegetable consumption, 2008-2011 combined

4.6 PHYSICAL ACTIVITY BY PARENTAL PHYSICAL ACTIVITY, 2008-2011 COMBINED

Children's physical activity levels grouped according to whether their parents met the adult physical activity recommendations are presented in Table 4.7. Note that in all years the survey included a boost sample of households in which children were interviewed but adults were not. The results in this section are therefore only based on children in the main sample where at least one of their parents was also interviewed (and answered the physical activity questions). The data have been re-weighted accordingly to show the pattern of association between parental and child physical activity in households where we have a physical activity measure for parents. Complete information was more likely to be gained for mothers than for fathers (this will be due to more single-parent families being headed by women than men, and differential response rates within households, with fathers less likely to respond than mothers).

When this analysis was last conducted (based on the 2008 and 2009 surveys),^[4] it showed that activity levels among mothers and fathers were 6-7 percentage points higher than for the population as a whole. This will, at least in part, reflect the age profile of people with children aged under 16 (they are less likely to fall into the oldest age groups, where physical activity levels are lowest). Fathers were more likely than mothers to meet the recommendations.

As was found with the 2008/2009 analysis, children were more likely to meet the physical activity recommendations if their mothers did so too.^[4] This was true for both sexes: 80% of boys and 71% of girls whose mothers met the adult recommendations met the child recommendations themselves. This compared with 72% of boys and 62% of girls whose mothers did not meet the adult recommendations. However, in common with previous analysis, children's activity levels were not associated with father's activity levels.
Table 4.7