Running: downhill

By: Johnny-Wei Bai

For years, people have recognized that physical exercise improves cardiovascular and mental health, controls weight gain, and enhances academic performance. In fact, some even estimate that 20 per cent of premature deaths could be prevented by regular physical activity. Despite the benefits of physical activity, recent studies show that 85 per cent of Canadian adults do not fulfill the recommended 150 weekly minutes of moderate-to-vigorous exercise. Looking at the bustling activeness in young children, one may wonder at what stage of development this drop in exercise level comes about. Well, it is known that decline in physical activity occurs most drastically in adolescents transitioning into early adulthood, especially from high school into college/university.

To further explore this phenomenon, a recent research study was headed by Matthew Kwan, a post-doctoral fellow at McMaster University's Department of Family Medicine. Participants for this prospective cohort study were recruited from the Canadian National Population Health Survey; in total, 683 adolescents of ages 12-15 were followed until they turned 25-27 years old. During this period, scientists looked at factors such as physical activity, education status, binge drinking, and smoking levels in both males and females. Comparing such a wide-range of factors allowed researchers to evaluate whether decline in physical activity is truly as big of an issue as other, more publicized health-risk factors.

Results showed that the average physical activity level across all participants decreased by a drastic 24 per cent, with a steeper decline in college/university males than in females. This difference across genders, however, may be because females in this study generally exercised less than males did, even in high school. Other health-risk behaviours, such as smoking and binge drinking, predictably increased during the high school-university transition, likely because of reduced parental influence and greater social pressures in post-secondary settings. Although levels of drinking and smoking began to plateau in later years, physical exercise levels continued to decline in adulthood.

Kwan’s findings suggest that an increase in unhealthy behaviours in early adulthood puts university and college students at greater risk of future health complications. It is commonly known that excessive smoking and drinking can cause various cancers, lung conditions, and cardiovascular diseases. McMaster researchers claim that in addition to the usual focus on preventing negative behaviour, health promotion strategies should emphasize the benefits of positive health activities such as physical exercise. Kwan called for greater efforts in targeting the decline in physical activity levels in adolescents to encourage healthy life-long habits.