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Exercise as it relates to Disease/Sleep duration and sedentary behaviour's effect on weight of children

What is the background to the researchEdit

The article “Sleep duration and risk of obesity among a sample of Victorian school children” [1]. BMC has over 300 peer-reviewed journals, which explore science, technology, engineering and medical topics.

Owing to the obesity epidemic, with the World Health Organization (WHO) estimating an alarming 41 million children under the age of 5 as obese in 2016 [2], this research is useful as it specifically focuses on Australian children.

Until recently, majority of work on childhood obesity has targeted healthy eating through the content of school canteens [3] However, sleep duration (over or under 10 hours per day), through its links to amount of physical exercise, sedentary behaviour and subsequent weight status this article brings importance to the multifactorial nature of the health issue.

Where is the research fromEdit

This was a randomised control trial where participants were randomly taken from a larger Victorian State study. The research collected data from a range of measures including:

  • Height and weight
  • Accelerometry derived physical activity
  • Sedentary time
  • Self-reported sleep duration
  • Age
  • Gender
  • Environmental factors

What kind of researchEdit

The study conducted in 2013, used a “sub-sample of 298 grades four (n = 157) and six (n = 132)” students from a “larger state based cluster randomized control trial in 2013” [4].

Outcomes of the studyEdit

Most important measures of the study were Sleep Duration, BMI, Waist Circumference, Physical Activity and Sedentary Time. The combination of the latter four measures when separated into participants >10 hours and <10 hours sleep duration was telling to its importance and need for greater focus on the health of children. Not enough focus has been put into sleep duration and patterns in schools and interventions targeting obesity in children.

Sleep duration (hr) (%)
<5 2.1
5 1.0
6 2.8
7 3.1
8 7.3
9 17.0
10 38.0
11 18.7
>12 10.0
Measures (%)
Insufficient (<10hrs/night) 33.2
Sufficient (>10hrs/night) 66.8
Overweight/Obese 30.5
TV in bedroom 31.8
Computer/Elec. games in bedroom 39.3

From the study 33.2% of participants had insufficient sleep. Of these participants the following was discovered:

  • Overweight 25%
  • Obese 14.6%

Results supported parts of the hypothesis, that “compared with sufficient sleepers, children with insufficient sleep durations will more likely be overweight or obese and record lower average daily PA and higher average daily ST” [5]. While children that had shorter sleep duration's were more likely to be obese, there was no link with physical activity and sedentary time duration. The standard measure of this was <10 hours sleep or >10 hours sleep. Moreover those that had >10 hours sleep were healthier (BMI and WC).

Impacting the validity of results, limitations of the study included measurement of sleep hours, with participants self-reporting the time they fell asleep. Collection of data could have been better collected through the use of monitors. PA and ST were measured in a more accurate way through the use of waist-worn AntiGraph GT3X or GT3X+ accelerometer. Both PA and ST were measured in total over the day rather than consecutive blocks of time. This allowed the capture of what each participant actually did and helped explain sleep duration and the effect on their health.

What conclusions can we take from this researchEdit

There is a clear link between sleep duration and health that needs to be taken as seriously as diet and exercise.

Future research needs to address the possible reasons for lack of sleep, such as the use of devices in bed. Although it does provide some statistics, with 31.8% of participants having a TV in the bedroom and 39.3% having computer or electronic games in the bedroom, it does not provide information on times of duration of use. Therefore, the assumption can be made that these numbers correlate with the percentage of participants that get insufficient sleep.

Future work also needs to focus on school and parental education, to create a culture that identifies the risks associated with a lack of sleep and sleep latency. As further research has shown that owing to the rise in use of devices with 'blue screens', children are going to bed but not going to sleep and this has significant effects on sleep latency and REM sleep, when compared to controls [6].

Therefore, future research should identify the link between insufficient sleep, use of electronic devices and obesity, with the hope that findings create more attention towards the issue.

Practical adviceEdit

Strategies to combat this problem need to be provided to both children and their parents as study findings indicate a significant association between parents and children and media devices use during the weekday and in the bedroom.

"Efforts to reduce media in parent bedrooms may enhance interventions targeting reduction of media use among children, especially those with higher BMI” [7]. Ways to effectively change behaviour and culture within the family home could be to leave devices outside in a communal area when going to bed. Alternatively, an app to link the child’s to the parents phone to lock it or access to apps after a certain time in a day could have a similar effect.

To conclude, children need over 10 hours sleep each night to give them the energy to positively influence their health outcomes through physical exercise. Closer monitoring of children’s sleep patterns e.g. are they in bed on a device or asleep, should be exercised by parents.

Further information/resourcesEdit


  1. BioMed Central. Sleep duration and riskk of obesity among a sample of Victorian School Children [Internet]. Victoria, School of health and social development; 2016; cited 2018 September 8. Available from:
  2. World Health Organisation. Obesity: preventing and managing the global epidemic [Internet]. Geneva: World Health Organisation; 2000 [updated 2004]; cited 2018 September 15]. Available from:
  3. Australian Government Department of Health. National Healthy School Canteens: Guidelines for healthy foods and drinks supplied in school canteens [Internet]. Canberra: Australian Government Department of Health; 2014 [cited 2018 September 17]. Available from:$File/Canteen%20guidelines.pdf
  4. BioMed Central. Sleep duration and riskk of obesity among a sample of Victorian School Children [Internet]. Victoria, School of health and social development; 2016; cited 2018 September 8. Available from:
  5. BioMed Central. Sleep duration and riskk of obesity among a sample of Victorian School Children [Internet]. Victoria, School of health and social development; 2016; cited 2018 September 8. Available from:
  6. Higuchi S, Motohashi Y, Liu Y, Maeda A. Effects of playing a computer game using a bright display on presleep physiological variables, sleep latency, slow wave sleep and REM sleep. J Sleep Res [Internet]. 2005 September [cited 2018 September 17];14(3):267-273. Available from:
  7. Lee J, Kubik MY, Fulkerson JA. Media Devices in Parents’ and Children’s Bedrooms and Children’s Media Use. Am J Health Behav [Internet]. 2018 Jan 1 [cited 2018 September 17]; 42(1):135-143. Available from: