The Cooper Institute

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH


Physical activity - stop the decline before it happens!

Posted in
Move more

Thursday, Jan 12, 2012

Have you ever watched a kid run around and think, “Wow, they are on the move nonstop?” Research has shown that indeed physical activity declines as we age. This decline, however, is not linear in nature nor does it follow the same path for males and females. Recent research published in the American Journal of Preventative Medicine explored this relationship.1 The study included 640 Canadian adolescents whose ages were between 12- and 15-years-old at baseline. Participants were interviewed every 2 years for seven cycles of the National Population Health Survey (NPHS). Across the 12 year period of the study there was a 24% decrease in physical activity overall from adolescence into early adulthood. This was equivalent to approximately 1 MET/day. When gender was accounted for, however, a steeper decline was shown for males (30% decrease or 1.54 METs/day) than for females (17% decrease or 0.59 METs/day). The authors noted that the greatest declines for females probably happen before or during adolescence accounting for the gender differences found here. In fact research has shown a 50% decline2 in activity of adolescent girls up to even an 83% decline!3 This study also looked at binge drinking and smoking and while these unhealthy behaviors also rapidly inclined during this time, they have been shown to level off or decrease in adulthood whereas physical activity has been shown to continue to decline.

This research is significant because it can help direct our intervention efforts. A great deal of research and many resources are dedicated to increasing the physical activity levels of adults but they have traditionally been geared more for those who are of middle age. And while this is worthy, these findings indicate that efforts need to begin earlier and be geared towards preventing the decline that occurs at this particular age. Research should be conducted to learn which strategies will be most effective with this group, as they potentially could be very different than those that are currently in use. Large efforts are made at preventing binge drinking and smoking in this population, and again while these are worthy, preventing the decline in physical activity should be viewed as just as important, especially since the decline of physical activity continues into adulthood. Focusing on preventing the decline may finally be the answer to significantly affecting physical activity levels as it is much easier to maintain your fitness than to get it back once it is lost!

1Kwan MY, Cairney J, Faulkner GE, Pullenayegum EE. Physical activity and other health-risk behaviors during the transition into early adulthood. Am J Prev 2012; 42 (1): 14-20. 2Heath BW, Pratt M, Warren CW, Kann L. Physical activity patterns in American high school students: results from the 1990 Youth Risk Behavior Survey. Arch Pediatr Adolesc Med 1994; 148: 1131-6. 3Kimm SY, Glynn NW, Kriska AM, Barton BA, Kronsberg SS, Daniels SR, Crawford PB, Sabry ZI, Liu K. Decline in physical activity in black girls and white girls during adolescence. N Engl J Med 2002; 347 (10): 709-715.