Exercise as it relates to Disease/The effect active travel has on the BMI's of children

Background to the Research
Active commuting is opting to walk, cycle, skate or run, as a means of transportation. Increasing the number of individuals engaging in active travel is important as it can have a positive impact on not just the health of the population but the urban environment as well. For the general population, active travel can reduce overall obesity levels, and is an effective preventative measure against sedentary diseases like diabetes, heart disease and certain cancers. In an Urban environment, increasing the number of people who engage in active travel can reduce traffic congestion, lower greenhouse emissions and reduce the number of motor vehicle accidents. The rate of children actively commuting to school is declining in the US so research on how to effectively increase the health of children is crucial.

Where is the Research From?
This research was conducted in Nebraska by K. A. Heelan, a professor at the University of Nebraska. The research is reputable as it was conducted by a professor at a university where research is of better quality. The findings from the research are not transferable as the data was only collected in rural areas in Nebraska. You cannot mimic these conditions in Australia as the climate is vastly different.

Type of Research
This research was a cross-sectional, observational study. These studies are a cheap and effective way of estimating the prevalence of behaviours or disease within a sample of the population. This study is not longitudinal as only one assessment of the children was made, therefore the impact of active commuting on the prevalence of overweight cannot be measured. Cross-sectional studies only identify associations and not causations.

What did the Research Involve?
The research was undertaken in Nebraska where 600 school children from 8 rural schools were invited to participate in the 5-month study. Only 60% of students invited, participated in the study. The final sample size was further reduced to 320, due to 12% of participants not completing the study. The decline responses to the invitation to participate in the research are evidence of non-response bias, this bias can result in a sample that does not represent the population because participants who chose to take part in the research differ to those who do not. Non-response bias is a common issue for cross-sectional research.

Staff took initial anthropometry measures to establish baseline data. Body weight, height, BMI and skinfold measurements were all taken. Questionnaires were then given to the participants during a PE class. The questionnaires measured the total minutes of performing physical activity. Total active commuting time was determined by using an active commuting school index (SI). SI was then calculated by the number of times the child actively commuted to school during each assessment week by the distance travelled to and from school. During the first month of testing PE teachers sent home a questionnaire for parents to further identify the perceived barriers to active travel.

Basic Results
The research found that those participants who actively commuted spent significantly more time in moderate activity than those who were driven to school. Interestingly no association was found between SI and BMI. Majority of trips to school were made by car, only 37% of trips made to and from school were active commuting trips. Half of the children lived less than 1.6km from the school, of that half, only 9% active commuted to school more than 75% of the time each week.

As proximity to the school decreased, the likelihood that the students were to engage in active commuting to school increased. The rate of travel was lower going to school than that after school.

What conclusions can we take from this research?
An increase in both motor vehicle use and obesity rates in children has contributed to the decline in active travel of school children. The study did identify the following trends:


 * The more physical activity accumulated by active travel, the greater the participants BMI was. This positive association was identified in the overweight children where they gained 34% more than their normal weight peers.
 * Children engaging in actively travel to and from school spent more time in moderate-intensity physical activity throughout the day than those choosing motor vehicles as a mode of transportation.
 * The questionnaire sent to parents identified that the distance of their homes from school was the biggest barrier to their children not actively commuting

The positive association of BMI and active travel could be due to the individuals compensating for this rise in activity by reducing the amount of physical activity they perform when out of school home. A restrictive rate of physical activity at schools has been found to lead to an increase of sedentary behaviour of students after school, therefore more children engaging in active travel will lead to high rates of physical activity in schools. The distance from home to schools may be listed as the number one barrier to engaging in active travel because the study was undertaken rurally. The cities may not have the correct infrastructure in place to facilitate safe active travel.

Practical Advice
The following advice should be taken into consideration when attempting to increase active travel methods in school children:


 * Improve or build local infrastructure to create safe active travel routes to school.
 * Increasing the rate of physical activity in schools will increase the rate of active travel because children who engage in higher levels of moderate intensity physical activity are more likely to engage in active travel.
 * In overweight children, stop the increase in BMI, children should engage in physical activity outside of school to combat the compensation methods as a result of the increase of physical activity due to active travel.

Further Information and Resources

 * Safely letting you child independently travel to school: https://www.vichealth.vic.gov.au/media-and-resources/publications/parental-fear
 * How to get children to engage in active travel: https://www.healthykids.nsw.gov.au/downloads/file/campaignsprograms/Walk-and-wheelOnceaWeek.pdf
 * Developing and promoting active travel routes to schools: https://www.geelongaustralia.com.au/healthygeelong/schools/article/item/8d1a21a692481a2.aspx