Too Much Sport for Teenagers May Be bad for health

Peak scores of well-being for teenagers occurred with about 14 hours a week of sport practice, or twice the recommended 7 hours, but higher sport durations independently predicted poor well-being, according to a Swiss survey study published online November 21 in the Archives of Disease in Childhood.

“Sport practice is widely encouraged, both in guidelines and in clinical practice, because of its broad range of positive effects on health,” write Arnaud Merglen, MD from the Institute of Social and Preventive Medicine at the University of Lausanne in Switzerland, and colleagues. “However, very limited evidence directly supports this statement among adolescents and the sport duration that we should recommend remains unknown. We aimed to determine sport durations that were associated with poor well-being.”

Between February 2009 and January 2010, the investigators recruited 1245 adolescents, aged 16 to 20 years, from various settings in the French-speaking part of Switzerland, including sport centers, peers of sport-practicing adolescents, and Web sites.

Using answers to a Web-based questionnaire, the investigators categorized weekly sport practice of the participants into 4 groups, from low (0 – 3.5 hours) to average (approximately equal to the recommended 7 hours; 3.6 – 10.5 hours), high (≈14 hours; 10.6 – 17.5 hours), and very high (>17.5 hours). The 5-item World Health Organization well-being index, scored from 0 to 25, with scores below 13 indicating poor well-being, allowed evaluation of well-being.

Participants had an average age just younger than 18 years, half were male, and 8.9% were overweight or obese. Sports participation was low in 35.2%, average in 41.5%, high in 18.5%, and very high in 4.8% of participants.

Very High Sports Practice Predicts Low Well-Being

The average well-being score for the entire sample was 17. Those in the very high sports practice group had more than twice the risk for poor well-being than those in the average group (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.11 – 4.72), as did those in the low-activity group (OR, 2.33; 95% CI, 1.58 – 3.44). In contrast, those in the high-activity group had about half the risk for poor well-being as those in the average group (OR, 0.46; 95% CI, 0.23 – 0.93).

“We found an inverted, U-shaped relationship between weekly sport practice duration and well-being among adolescents,” the study authors write. “The peak scores of well-being were around 14 h per week of sport practice, corresponding to twice the recommended 7 h. Practicing higher sport durations was an independent risk factor of poor well-being.”

Limitations of this study include possible selection bias, observational design, reliance on self-report, and unknown direction of causality.

“[H]igher levels of pro-inflammatory cytokines have been reported in very high and chronic sport practice, with a negative impact on physical and mental health,” the authors conclude.

“These results highlight the importance for physicians, caring for adolescents, to follow-up their level of sport practice and concurrently inquire about their well-being.”

Source: Med scape