Girls who play sports more than 8 hours per week are twice as likely as their less active peers to suffer a stress fracture, a new study1 finds.
Not surprisingly, the girls most at risk were those engaged in three activities (running, basketball and cheerleading/gymnastics) which involve repeated jumping and landing and place particularly high stress on bones. The risk of injury increases about 8 percent for each extra hour of activity over four hours per week.
The study, the first large general-population-based study of stress fracture rates among adolescent and young adult girls, is reported in the Archives of Pediatric Adolescent Medicine.
The results prompted the study's authors to recommend that those "who supervise athletic programs for young female runners, basketball players, gymnasts, and cheerleaders promote varied training in non-impact or intermediate impact activities to decrease the cumulative amount of impact as well as reducing the hours spent training in [such] high-impact sport[s]."
Because physical activity during childhood and moderate activity during adolescence may increase bone mass density and thus help to protect against osteoporosis in adulthood, "It is very important that we encourage girls to be active, but to not spend 15 or 20 hours per week engaged in high impact sports", said Alison Field, ScD, the study's lead author and an Associate Professor of Pediatrics in the Division of Adolescent Medicine at Children's Hospital Boston in an interview with MomsTeam.com.
"Our study provides evidence that girls who participate in high impact sports, such as running, gymnastics, cheerleading, and basketball, are more likely to develop stress fractures, so we recommend cross-training with activities that are low or moderate impact and activities that use different patterns of movement, replacing some high impact training with low and moderate impact activity, and not engaging in extremely high levels of high impact sports. .
The study's recommendations, wrote Dr. Field in the study, are "particularly critical" given the movement of youth athletes "away from playing a different sport in each season to focusing on a single sport throughout the year. [1] "
Nevertheless, Dr. Field wrote, "the strengths of the study far outweigh the limitations," among them that it stands as the largest prospective study of adolescents, that data was collected at regular intervals (every 12 to 24 months), was gathered before the onset of stress fracture, and because information was available on a mother's history of low BMD and osteoporosis as well as information from the participant on age at menarche, body weight, disordered eating, and physical activity.
Posted April 9, 2011
Links:
[1] https://www.momsteam.com/node/1215
[2] https://www.momsteam.com/node/3352
[3] http://www.archpediatrics.com
[4] https://www.momsteam.com/stress-fractures/stress-fractures-in-high-school-athletes-growing-problem
[5] https://www.momsteam.com/sports/track-field/safety/overuse-injuries-in-track-field
[6] https://www.momsteam.com/successful-parenting/-overuse-injury-epidemic-result-year-round-play-too-many-teams-at-same-time
[7] https://www.momsteam.com/overuse/preventing-overuse-injuries-in-youth-athletes