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Teenagers have long been told that being active and 1. (take) part in sports is good for their health. But new research suggests that too much sport for teenagers could negatively affect their well-being just as much as too 2. sport.

The US Department of Health and Human Services suggests that young people 3.(age) between 6 and 17 work 4.at least 60 minutes a day, 7 hours a week. But researchers from Switzerland say their study suggests that 14 hours of physical activity a week is best for promoting good health in teenagers. However, more than 14 hours 5. (appear) to be harmful to their health. To reach their findings, they had 1,245 teenagers 6.(survey) in their research.

All participants (参与者) were required to answer questions about height and weight, sports practice, sports 7. (injure) and well-being. Their well-being was measured using the Word Health Organization (WHO) Well-being Index, 8. provides scores between 0 and 25. Of the participants, 50.4% were male. Almost 9% of these males were overweight. The overall 9. well-being score for all participants was 17.

The researchers divided sports participants into low, average, 10. , and very high. The researchers found that participation in the low and very high activity groups were more likely 11. (have) well-being scores below 13, compared with participants in the average group. The researchers found that the highest well-being scores were 12. a by participants who carried out around 14 hours of physical activity a week, but beyond 14 hours resulted 13. lower well-being scores.

The researchers suggest that doctors 14. care for teenagers should check their level of sports practice. Teenagers 15. (probable) need a supportive and closer follow-up of their health and well-being.