The U.S. military has become particularly interested in studying stress fractures. The overuse injury affects up to five percent of male military recruits, and up to 21 percent of females, and costs the Army millions of dollars annually in lost training expenses, according to a 2010 study.
Because the injury comes from repetitive, excessive stress on the bone, athletes are also at risk. Up to a third of track and field runners will experience a stress fracture at some point, while alpine skiers, basketball players, hikers with heavy packs, and football players often find themselves sidelined as well. Finland’s most successful slalom skier, Kalle Palander, struggled with a tibial stress fracture for three years. The tibia, or shin bone, is the most common place to get a stress fracture, making up nearly a quarter of all stress fractures and typically taking six to eight weeks to heal.
How to prevent it:
“Most commonly, training errors may be to blame,” says Dr. Jason Glowney, a Boulder-based sports medicine doctor, and author of a study on stress fractures in collegiate distance runners. “This can mean that the stress the athlete put on the bone outpaces the body’s ability to remodel or heal the tissue.”
One way to help avoid the injury is to carefully increase training volume and intensity. Many running coaches use the 10 percent rule, increasing a runner’s mileage no more than 10 percent per week. Runners who log more than 25 miles per week are at higher risk for a stress fracture, according to a study published last year.
Pay attention to diet. “This means getting in an adequate amount of vitamin D and calories for the training levels you’re undertaking,” Glowney says. The Food and Nutrition Board recommends adults get 600 IU of vitamin D per day. Fatty fish like tuna and salmon, along with vitamin D fortified foods like milk and breakfast cereals, are good sources of the bone-building vitamin. Make sure you’re taking in enough fuel; use this calculator to figure out calorie requirements.
Finally, doctors say that once pain and swelling in the shin begins, athletes should stop training and set up an appointment. “Many athletes will choose to race with stress bone injury and run the risk of that injury becoming a full-blown fracture in itself,” Glowney says. “In these situations the downtime can then become significantly greater and can disrupt an entire season and in some cases an entire career.”