Adolescents Let Physical Activity Slide After 7th Grade

Ruzanna Harutyunyan's picture

By the time they reach ninth grade, most adolescents abandon the physical activities they enjoyed in seventh grade; and the more vigorous the activity, the more likely they are to drop it.

Although some older adolescents rekindle their interest, it still does not return to seventh-grade levels, according to a study in the July issue of the American Journal of Preventive Medicine.

Secondary school students in Montreal reported their participation in 29 physical activities over five years. Although participation in team-based activities started high at 94 percent in seventh grade, 50 percent of girls and 31 percent of boys had dropped out by the end of high school. Conversely, only 10 percent of adolescents abandoned their individual activities during the same period.


According to Mathieu Belanger, the lead study and research director at the New Brunswick Medical Training Centre, a large majority of adolescents in Canada do not achieve the recommended 90 minutes of moderate-to-vigorous activity every day. Since habits formed during adolescence tend to continue into adulthood, he is concerned that this inactivity could lead to substantial health concerns, such as diabetes and obesity, later in life.

Belanger’s numbers also reflect a return to certain activities or an interest in new ones. The most popular activities in seventh grade — such as walking, running and physical conditioning — had the highest levels of reuptake five years later (around 50 percent). In fact, walking was the only activity that girls continued to participate in at the same level over time.

Elissa Jelalian, an associate professor in psychiatry and human behavior at Brown Medical School, agreed that the decrease in vigorous physical activity among adolescent girls, which has significant health implications, particularly is noteworthy. “Given that adolescents are more likely to maintain individual physical activity,” she said, “efforts should focus on identifying strategies that enhance the intensity of this type of activity.”

Belanger said that the results provide insight on the most effective time to introduce programs aimed at encouraging healthy activity levels. For most activities, the best time seems to be early adolescence, although schools should not ignore older age groups, even though fewer of these individuals continue to be active.

Both Belanger and Jelalian say that the knowledge will help school boards and public health authorities plan sports programs that remain high on this age-group’s to-do list, when interest traditionally wanes.