Although many kids don’t exercise enough these days, some may be doing too much of the wrong type.
Adolescent girls engaged in high-impact activities, specifically basketball, running, gymnastics and cheerleading, are at increased risk of developing stress fractures, which can undermine their long-term bone health, according to a study published in the journal Archives of Pediatrics and Adolescent Medicine.
“Stress fractures are painful and, if not detected early and given time to heal, they can pose a risk for fracture, deformity or growth disturbance requiring surgical treatment,” said the lead author of the study, Alison Field of Children’s Hospital and Harvard Medical School in Boston.
The findings are based on a study of 6,831 girls, aged 9 to 15. Each hour per week of high-impact activity increased the risk of stress fractures by about 8 per cent.
“Some weight-bearing activity is healthy for bone, but we are seeing adolescents who are spending 20 or more hours per week training for and playing their sport and that is excessive,” Dr. Field noted in an e-mail. To make matters worse, some adolescents specialize in a single sport at a very young age. The stress fractures don’t heal properly “because season after season the athlete is doing the same pattern of movement and impact.”
She suggests that “It would be better to think about replacing some training time in high-impact activities with lower-impact alternatives (such as cycling), more cross-training, and less specialization in one sport throughout the year.”