2. Achilles Tendinitis
The Achilles tendon connects the two major calf muscles to the back of the heel. Under too much stress, the tendon tightens and becomes irritated (tendinitis). It makes up 11 percent of all running injuries; eight percent of runnersworld.com poll respondents dealt with it this past year.
WHO'S AT RISK?
Runners who dramatically increase training (especially hills and speedwork) and have tight, weak calves are vulnerable.
CAN YOU RUN THROUGH IT?
"If you have any pain during or after running, stop," says Amol Saxena, D.P.M., a sports podiatrist in Palo Alto, Calif."This is not an injury to run through."
If you catch a minor strain early, a few days off might be sufficient healing time. If you keep running as usual, you could develop a serious case that may take six months to go away.
Five times a day, apply ice. Strengthen the calves with eccentric heel drops: Stand with the balls of your feet on a step. Rise up on both feet. Once up, take your stronger foot off the step. Lower down on your injured foot, dropping your heel below the step. Rise back up, return your other foot to the step. Do 20 reps. Pool-run, use an elliptical machine, and swim, but avoid cycling unless it's not painful.
PREVENT A RELAPSE
Strong calves protect your Achilles from flare-ups, Dr. Price says, so do heel drops daily. Avoid aggressive calf stretching and wearing flip-flops and high heels, all of which can irritate the Achilles.
Shannon Rowbury, 1500-meter bronze medalist (2009 World Championships), wears compression socks for hard workouts to relieve Achilles tightness.
"It's made a huge difference," she says.
Ankle Alert: How to Proceed
You experience severe pain and swelling above your heel—even when not running. Standing up on your toes causes pain.
There is a dull pain around your heel at the end of your run that continues to linger afterward, but eventually goes away when iced.
You feel no pain when pinching the tendon, starting at the heel and working your way up your leg, toward your calf.