It turns out that strengthening bone to avoid fractures starts at a very young age.
Physical activity, such as the exercise children get in school gym classes, is important for fighting obesity, but the latest research suggests it may help to keep bones strong as well.
For six years, researchers from Skane University Hospital in Malmo, Sweden, followed 808 boys and girls ages 7 to 9 who were asked to participate in 40 minutes of physical activity daily during school. The scientists recorded the children’s skeletal development, and documented any reports of fractures and compared these results with those of a similarly aged control group that completed 60 minutes of physical activity over a week.
Reporting at the American Orthopaedic Society for Sports Medicine’s Specialty Day in Chicago, the researchers found that during the study period, children in the group that exercised daily reported 72 fractures, while those in the control group recorded 143 fractures. Those who were physically active for 40 minutes a day also showed higher bone density in the spine compared with those who did not exercise as much. Bone density is an indication of bone strength, and the denser bone density is early in life, the stronger bones remain decades later, when natural thinning of bones weakens the skeleton and increases the risk of fractures and breaks.
To correlate these results with fracture risk later in life, the researchers also studied 708 former male athletes in their 60s and 70s and compared their fracture rates and bone-density scores with those of healthy men of the same age who had not been trained at an elite level. The former athletes showed a smaller rate of loss in bone density on average than the nonathletes, suggesting that their bones were better able to avoid fractures.
“According to our study, exercise interventions in childhood may be associated with lower fracture risks as people age, due to the increases in peak bone mass that occurs in growing children who perform regular physical activity,” lead author Dr. Bjorn Rosengren, of Skane University Hospital, said in a statement. “Increased activity in the younger ages helped induce higher bone mass and improve skeletal size in girls without increasing the fracture risk. Our study highlights yet another reason why kids need to get regular daily exercise to improve their health both now and in the future.”
The results confirm previous findings on the benefits for bone of regular exercise. One study found that compared with sedentary women, those who are the most active have the highest bone density and lowest risk of the bone-thinning disorder osteoporosis. Bones become more porous and brittle with age, as cells responsible for building bone become less active and can no longer keep up with the cells that destroy and remove old bone cells. Physical activity can shift this balance toward maintaining a healthy amount of bone growth, say experts.
Our partner Greatist also wrote about what types of exercise can maintain bone health:
What type of exercise is most effective? Weight-bearing exercises like running, walking, jumping rope, skiing and stair climbing keep bones strongest. Resistance training has also been shown to improve bone health in several studies, so pick up the weights after going for a jog. Bonus for the older readers: improved strength and balance helps prevent falls (and the associated fractures) in those who already have osteoporosis.
So while fractures aren’t typically a problem for young children (unless they have a major fall), it’s never too early to start protecting against the future risk of bone problems. “With the current knowledge, we ought to recommend training in young years as a strategy to prevent fragility fractures at old ages,” the authors wrote in the study. Just one more reason for children to trade in the TV for a few laps around the track.