HIGH IMPACT SPORTS INCREASES BONE DENSITY

By Amy Norton

Young girls who do artistic gymnastics build more bone and muscle. Photo / Reuters

The high-impact tumbling of gymnastics may boost young girls' muscle mass and bone density, a small study claims.

Spanish researchers found that young girls who participated in artistic gymnastics had greater muscle mass and bone density than their peers whose activities were limited to gym class.

What's more, they also had denser bones and more muscle than girls who practised rhythmic gymnastics, a sport that requires fitness and agility but does not include the particularly high-impact moves of artistic gymnastics.

The findings suggest that before they reach puberty, girls should take up activities that put some stress on the bones in order to strengthen them, the study authors report in the International Journal of Sports Medicine.

Like muscle, bones respond to exercise by becoming stronger, particularly higher-impact activities like jumping and sprinting. The years before puberty were an especially opportune time to boost bone density with exercise, explained the study's lead author, Dr German Vicente-Rodriguez of the University of Zaragoza.

For girls, building bone density from an early age may reduce their risk of the bone-thinning disease osteoporosis later in life.

Any sports that include jumping, sprinting and rapid direction changes might aid in bone development, said Dr Vicente-Rodriguez. That included soccer, basketball, martial arts and lacrosse. Swimming and bicycling, because they did not require the body to work against gravity, were not good bone-builders, Dr Vicente-Rodriguez noted. Nonetheless, since they did improve cardiovascular fitness, they were still healthy activities.

The findings are based on fitness tests and bone and muscle scans from 35 prepubescent girls - nine who were part of artistic gymnastic clubs, 13 who practised rhythmic gymnastics and 13 who did not exercise outside school.

Overall, the researchers found, both groups of gymnasts were more physically fit than their sedentary peers, and had substantially less body fat. However, the artistic gymnasts had the greatest muscle mass and tended to have higher bone density, particularly in the arms.

This did not mean, however, that the tumbling of artistic gymnastics was "healthier" for girls, said the doctor. Instead, children should take up varied activities.

-          Reuters