1. Achilles Tendinitis
The Problem: Your Achilles tendons tense and extend with each stride. Weak calves strain them.
The Big Risk: Running uphill increases the load on your calves and Achilles, says Bryan Heiderscheit, P.T., Ph.D., of the University of Wisconsin sports medicine center.
The Fix: Do calf raises: Balance on a step on your right foot so your heel hangs off it; raise your left foot behind you. Rise onto your toes; then lower your heel as far as you can. Do 2 sets of 10 to 15 reps with each leg twice a week.
More: Understanding Tendon Injuries
2. Iliotibial Band Syndrome
The Problem: The IT band is a fibrous tissue on the outside of your thigh that stabilizes your knees and hips. If your hips and knees twist too much, the IT band rubs your lateral femoral condyle, a prominent part of your thigh bone, causing pain on the outside of your knee.
The Big Risk: A long stride increases force on your knees and IT bands.
The Fix: To shorten your stride, boost your step rate by 5 to 10 percent, Heiderscheit says. Try to avoid landing hard on your heel, and keep your knee flexed about 20 degrees. Have a friend take video of you so you can check your form. Find out the real reason you're hurting by taking note of the hidden cause of your pain.
More: How to Prevent and Treat Common Running Injuries
3. Shinsplints
The Problem: You feel pain and soreness because your tibialis posterior muscle is pulling away from your shin bone. This muscle works with a larger calf muscle, your soleus, says Reed Ferber, Ph.D., director of the running injury clinic at the University of Calgary. "Your tibialis posterior is overworked and has to pull more of its weight," Ferber says.
The Big Risk: Weak muscles can expose you if you're new to running or returning after a hiatus.
The Fix: Strengthen your tibialis posterior and soleus muscles with calf raises. Also try seated ankle invertors: Sit with your leg straight and loop a resistance band around your foot. Making sure your leg doesn't rotate, pull the top of your foot inward for 2 seconds, and release for 2 seconds. That's 1 rep. Do 1 set of 10 reps a day, working up to 3 sets a day. (Another suggestion: You can also Fix Your Health with Massage, which is a proven health and mood treatment.)