Children's exercise habits reflect those of their parents

Concerned that your child is getting fat? You can do something about it simply by increasing your own physical activity. Studies have shown that the activity of a parent correlates with that of their child.

"At the school level, we can encourage more exercise, but ultimately the habits of the family are more important," says Dr Patrick Ip, board member of the Hong Kong Child Health Foundation and clinical associate professor at the department of paediatrics and adolescent medicine at the University of Hong Kong.

About 27 per cent of Hong Kong school students aged six to 19 years are overweight or obese, according to data presented by Ip at a press conference on January 5.

Detailed health and fitness data was collected from 173 schools for a total of about 100,000 students in the 2013/14 school year. The schools were part of the School Physical Fitness Award Scheme, a population-based programme that started in 1990 to promote physical activity and fitness among students.

In 2013, the department of paediatrics and adolescent medicine developed a centralised online platform to facilitate the collection of students' detailed health and fitness data.

It found that the flexibility of the average Hong Kong schoolgirl was at the bottom of the Singaporean standard, and below their mainland counterpart's average.

The handgrip strength of 15-year-old Hong Kong boys was 27 per cent weaker than their peers in the mainland and Europe. Boys' cardiopulmonary fitness was also much worse than that of boys in Europe, although the difference among girls was less pronounced.

Overall, the physical fitness gap between Hong Kong children and those from other parts of the world widened with age.

"The trend is a gradual deterioration of physical fitness among Hong Kong children in the past 20 years," says Ip.

"The key reason is that parents have an overemphasis on their child's academic performance. They do not encourage their kids to exercise and do not spend time with their kids playing sports together. This, even though studies have shown that physical activity and sports can promote better academic performance."

Recent research by the National Jewish Health medical centre in Colorado, US found that when parents took more steps daily, their children increased their physical activity as well.

The study, published in the Journal of Physical Activity and Health in 2012, involved 83 families with overweight and obese children aged seven to 14. Children and parents were encouraged to increase their physical activity by walking an additional 2,000 steps per day. Mothers in all 83 families participated, while only 34 fathers took part.

On days that mothers reached or exceeded their 2,000-step goal, children took an average of 2,117 additional steps, compared to 1,175 additional steps when mothers did not reach their goal. Father-child activity had a similar pattern.

For each 1,000 additional steps a mother took, the child took 196 additional steps.

Another study by Duke Medicine published online in the International Journal of Obesity in 2013 found "a significant association" between healthy behaviour in children and a healthy home environment and parental role modelling.

Data from 190 children, aged two to five, whose mothers were overweight or obese, was gathered. This included the children's food intake and physical activity levels, and their environment, such as family policies about food and physical activity, accessibility of healthy versus junk foods, availability of physical activity equipment and whether mothers model healthy eating or exercise for their kids.

"It's hard for parents to change their behaviour, but not only is this important for you and your own health; it is also important for your children, because you are a role model for them," says Marissa Stroo, a co-investigator on the study.

Ip hopes that updates to the centralised online platform for data collection can help parents guide their children's physical activity and health habits.

New to the platform is the ability for the generation of straightforward graphs of students' data, so that parents can monitor their children's health and fitness trends from Primary One to Secondary Six.

Parents who worry about their children's academic performance should take heart: reams of research studies show that exercise boosts both physical and mental muscle.

The University of Illinois at Urbana-Champaign, for example, recently reported findings in The Journal of Pediatrics after a nine-month randomised controlled trial that put 221 prepubescent children through an after-school programme of moderate to vigorous physical activity for at least 60 minutes a day.

Half of the study subjects were randomly assigned to the after-school programme and the rest were placed in a wait-list control group

Fitness increased most in the exercise group over the course of the study by 6 per cent, compared to less than 1 per cent in the control group.

Children in the exercise group also demonstrated substantial increases in "attentional inhibition", a measure of their ability to block out distractions and focus on the task at hand. They also improved in "cognitive flexibility", which involves switching between intellectual tasks while maintaining speed and accuracy.

Children in the control group saw minimal improvements in these measures, in line with what would be expected as a result of normal maturation over the nine months, says University of Illinois kinesiology and community health professor Charles Hillman, who led the study.

Hillman says improvements in the exercise group were correlated with their attendance rate, which was related to greater change in brain function and cognitive performance.

Other recent studies show that children who exercise have less overall body fat and carry less fat around their abdomens, a risk factor for diabetes and heart disease.

Daily aerobic activities for younger, at-risk children could help reduce the symptoms of attention deficit hyperactivity disorder in the classroom and at home; and that exercise may help children cope with stress.

Here are some ideas on how to get active with your child:

• Join the WCRF-Wellcome Beat the Banana Charity Run on March 15 at TST Promenade. The 1km run is for children up to 12 years old, who must be accompanied by a parent. beatthebanana-hk.org
• Sign up for the Hong Kong Academy for Performing Arts M.A.D. (Martial Arts Dance) parent-child courses. It's said to help children aged 18 months to nine years "dance the fat away". excel.hkapa.edu
• Enrol your young one in a Rolly Pollies gym class. There are parent-child classes for children aged six months to eight years. rollypollies.com.hk
• Take a weekly family hike. hiking.gov.hk has many suggestions under the "FamilyWalk" category