When my husband and I were navigating our way through the "terrible twos" with our children we frequently heard comments from more seasoned parents such as, "If you think this is bad, wait until the teen years!"  Well, we have a few more years yet before we enter that phase of parenthood but, thanks to new research, when we do get to that point we have hopes of a less tumultuous ride.  Why?  Exercise.

     Data from a scientific study published in the March 2010 issue of the Journal of School Health suggest that adolescents who frequently participate in vigorous physical activity are less likely to engage in risky behavior such as marijuana use and are more likely to practice health promoting behaviors such as adherence to a healthier diet, use of stress management techniques, and following a better sleep routine.  The purpose of the study was to determine if the frequency and/or intensity of exercise influenced the health behaviors (health risk versus health promoting) of adolescents.  The subject population consisted of 822 eleventh and twelfth grade students (56% female; 44% male; average age of 17 years) from an ethnically and socioeconomically diverse school in the suburbs of northeast Florida.

     Subjects completed The Personal Development and Health Survey which provided information on their level of physical activity, dietary habits, sleep patterns, and use of cigarettes, marijuana and alcohol.  An adaptation of the Godin Leisure Time Exercise Questionnaire (LTEQ) was used to determine the students' intensity of exercise (moderate vs. vigorous) and frequency of physical activity over a seven day period (low = 0-1 time; medium = 2-4 times; and, high = 5 or more times).  Moderate physical activity was defined as "exercise that was non-exhausting" (e.g., slow bicycling) and vigorous physical activity was defined as "activities that cause the heart to beat rapidly" ( e.g., running).

     Researchers found that those students who participated in high levels of vigorous physical activity were less likely to smoke marijuana frequently and heavily.  Investigators also discovered that this population was more likely to get a better quality of sleep, to practice stress management techniques, and to follow a diet that included healthy carbohydrates and healthy fats when compared to individuals who participated in low levels of vigorous physical activity.  Although not statistically significant, there was a trend that showed that cigarette consumption was lower and occurred less often for participants who engaged in high levels of vigorous physical activity versus those students who participated in low levels of vigorous physical activity.

Interestingly, the data showed mixed results for the influence of moderate physical activity on health behaviors practiced by the adolescents.  Those students who participated in high levels of moderate physical activity consumed a diet that included significantly greater amounts of healthy fat and they engaged in more stress management techniques than those individuals who engaged in low levels of moderate exercise.  When comparing these two subsets, a trend was noted for the consumption of a diet consisting of more healthy carbohydrates for those involved in high amounts of moderate physical activity, but the results were not statistically significant.  No differences were found in sleep quality or in the use of marijuana, cigarettes, and alcohol when comparing the influence of high levels of moderate physical activity to low levels of moderate exercise.

     The researchers propose the following explanations for the positive role high levels of vigorous physical activity play in promoting healthy habits in adolescents:

• Engaging in high levels of physical activity may expose the adolescent to positive social influences which, in turn, promote healthy behavior.
• Social images frequently display physically active individuals engaging in other health promoting behaviors which may, as a result, positively influence an adolescent's decision.
• Individuals who participate in physical activity may be more inherently inclined to partake in other health promoting behaviors while avoiding unhealthy practices.

     The researchers conclude that their findings have significant implications in light of the fact that health behaviors adopted in adolescence tend to continue into adulthood.  Of particular importance is the finding that dietary practices, stress management techniques, and cigarette consumption are positively effected by participation in high levels of vigorous exercise since these factors contribute to the development of chronic diseases later in life.

     Unfortunately, activity levels start to decline when a child reaches adolescence, especially for females.  Adolescents need an hour of physical activity per day.  This can be accomplished through structured and unstructured activities.  Parents play a vital role in encouraging their children to be active.  If you are active yourself, your child will likely follow your example.  Exercise can be part of your family's daily routine (e.g., family bike rides or football games).  Also, support modes of exercise in which your adolescent can engage with friends, since socialization is a key component at this age.  Furthermore, speak with school officials to encourage policies that require curriculums to include daily physical activity throughout the school day.

     Exercise can play an important role in preventing risky health behavior practices during the adolescent years.  And, evidence indicates it can encourage the adoption of other behaviors, such as a consumption of a healthy diet, that promote health.  Adopting a lifestyle that includes exercise will help your adolescent to "shape up" his behavior, as well as his body.

Note:  Before beginning an exercise program or increasing the intensity level of a current routine, a physician's approval should be obtained, especially for older adults and those at risk for or who currently have chronic health conditions.

Resource:
J Sch Health. 2010 Mar;80(3):134-40. "Relationship between frequency and intensity of physical activity and health behaviors of adolescents," Delisle, T.T. et al.