Exercise as it relates to Disease/More play: physical activity results in happier and healthier kids

The article that was critiqued was, Liu J, Sekine M, Tatsuse T, Fujimura Y, Hamanishi S, Lu F et al. Outdoor physical activity and its relation with self- reported health in Japanese children: results from the Toyama birth cohort study. 2015 p. 920-927.

What is the background to this research?Edit

From a young age, children need to be encouraged to be physically active. In a way, this is already achieved as we learn how to walk and run as we grow and prosper. Due to their age, children do not understand the full health benefits of a physically active lifestyle; thats what this study attempted to find. A study has shown that children should accumulate an average of 60 minutes of physical activity every day, and that should be a mixture of aerobic and weight bearing exercise [1].

Before this study, there had been few studies done on examining the trends in engagement in outdoor physical activity as children grow and whether changes in physical activity at different ages affect children’s health[2].

This study looked at the preferences for and the frequency of physical activity among Japanese children, aged between 6 and 12 and the effects on their self-reported health based on data from the Toyama Birth Cohort study[2].

Where is the research from?Edit

The research in this study is from Japan, looking at the data attained from the Toyama Birth Cohort Study[2]. The Toyama Birth Cohort Study was focused on 10 438 children born over an 11 year period in the Japanese prefecture of Toyama[2]. Although the Toyama study spanned from ages 3 to 15, only data from the ages 6 to 12 years was collected for this study[2].

This study was supported by the Nishiyama Fund of the University of Toyama and the National Natural Science Foundation of China as well as given grants by the Ministry of Health and Welfare, the Ministry of Health, Labour and Welfare, Toyama Medical Association and the Japan Heart Foundation[2]. All of these organisations should not have any conflicts of interests when it comes to the final results for this study.

What kind of research was this?Edit

This study was a longitudinal study[2] which looks at continuous measures over a prolonged period of time[3]. Longitudinal studies are beneficial because they are useful when looking information over a large period of time, which would have helped the researchers to see the change of the children’s preferences and feelings towards physical activity over the study time. However, an issue with longitudinal studies is that some data could have been incomplete[3], which could have been due to a child dropping out of the study. This issue should not have effected the study too dramatically. Using this method of research would have been the best for looking at the preferences for exercise over this extensive time period.

What did the research involve?Edit

The participants of the Toyama Birth Cohort Study answered a self-administered questionnaire, where they answered questions relating to how much they liked physical activity, their frequency of participating in physical activity and their eating and sleeping patterns[2]. This questionnaire was very broad and did not specify what type of physical activity was partaken and how long for.

To find the child’s self-reported health, the researchers used a Japanese version of the Dartmouth Primary Care Co-operative project charts[2]. These charts measured six core aspects of functional status, one of these being overall health and change in health[4]. A chart consisted of a question referring to the specific functional status that was being measured to find out the participants level, with a five-point scale used[4]. This five point scale measures from no limitation to severely limited[4]. In relation to the change in health, it was measured from much better to much worse[4]. . The researchers then used a chi-square analysis to find the association between liking outdoor physical activity, participating in outdoor physical activity and good self-reported health[2]. Chi-squares are very common statistical tool when the data is needed for crosstabulation[5]. So for this study, processing the data in this format was most effective as it was looking at three different aspects.

What were the basic results?Edit

This study shows that there was a positive correlation between liking and participating in outdoor physical activity and the likelihood of reporting to have good self-reported help[2]. The majority of children that were questioned retained their interest for physical activity and were still physically active for the 6 years[2]. The preference for physical activity dropped as the children grew older and the proportion of children who actually engaged in physical activity was lower than the proportion who reportedly liked physical activity[2].

What conclusions can we take from this research?Edit

From this study, we know that children believe they are healthier when they enjoy and participate in physical activity. This has both positive and negative consequences. It shows that the children know that physical activity has many benefits for them and that if they enjoy it, they participate more. It is also encouraging that the majority of children interviewed were participating in physical activity and did enjoy it, compared to not participating.

A drawback of this study is that it only looks at the self-reported health of the children, not the actual health of the child. The children in this study were aged between 6 and 12 and we can only assume that they are more inclined to say that they are healthy, just because they do physical activity. Although we know that there are a multitude of health benefits that come from doing physical activity[6], these are lacking from this study and it only focuses on self-reported health which could mean that this study lacks some depth.

There were also no specifications on what type of exercise and for how long they participated in it for in this study. The kids may still not have been hitting the recommended guidelines even though they were stating that they participated in exercise. Guidelines set by the Australian Government outline just how much and what type of physical activity children should be getting[7]

Practical adviceEdit

As we understand that there is a link between children liking physical activity and having a positive self-reported help, we can now aim to make physical activity as enjoyable as possible for kids. If this can be done, more kids would enjoy it leading to more kids participating, which results in more higher self-reported health and hopefully, a generally healthier population.

It also helps us understand areas which may be lacking. So trying to retain kids to play sport for longer as they grow older as we do see a drop off. We want them to be playing and staying fit and healthy for as long as possible.

Further informationEdit

Below are a few links to various sources to further enhance this information:

Australian Government’s Physical Activity and Sedentary behaviour guidelines for not only children but all ages

Australian Government's fact sheet summary on guidelines for children

Australian Government's ways you can increase children’s physical activity levels


  1. Janssen I, LeBlanc A. Systematic review of the health benefits of physical activity and fitness in school-aged children and youth. International Journal of Behavioral Nutrition and Physical Activity. 2010;7(40).
  2. a b c d e f g h i j k l m Liu J, Sekine M, Tatsuse T, Fujimura Y, Hamanishi S, Lu F et al. Outdoor physical activity and its relation with self- reported health in Japanese children: results from the Toyama birth cohort study. 2015 p. 920-927.
  3. a b Caruana E, Roman M, Hernandez-Sanchez J, Solli P. Longitudinal studies. Journal of Thoracic Disease. 2015;7(11).
  4. a b c d van Weel C, Konig-Zahn C, Touw-Otten F, van Duijn N, Meyboom-de Jong B. COOP/WONCA Charts. 1995.
  5. Using Chi-Square Statistic in Research [Internet]. Statistics Solutions. [cited 1 September 2018]. Available from: http://www.statisticssolutions.com/using-chi-square-statistic-in-research/
  6. Miles L. Physical activity and health. British Nutrition Foundation; 2007.
  7. Australia's Physical Activity and Sedentary Behaviour Guidelines [Internet]. Health.gov.au 2017 [cited 18 September 2018]. Available from: http://www.health.gov.au/internet/main/publishing.nsf/content/health-pubhlth-strateg-phys-act-guidelines#apa512