Achilles pain in runners: load, rest and recovery

The Achilles tendon takes several times your body weight with every running stride. Most of the time it handles that beautifully. But when training changes faster than the tendon can adapt, it starts to protest, and runners know the feeling: stiffness first thing in the morning, pain during the first mile that eases as you warm up, and a tendon that feels thick and tender to squeeze.

Why it happens

Achilles tendinopathy is a problem of load. It’s common in runners, and in anyone who suddenly increases their activity.^[1] Training characteristics, such as how much, how fast and how quickly volume changes, are among the strongest risk factors for running injuries in general.^[2]

Typical triggers:

• a jump in weekly mileage,
• adding hills, speed sessions or a new race distance,
• switching to lower-drop or minimal shoes too quickly,
• tight or weak calves,
• returning after a break at the same volume you left off.

Midportion or insertional?

• Midportion: pain and thickening about 2 to 6 centimeters above the heel. The most common type in runners.
• Insertional: pain right where the tendon attaches to the heel bone, often worse in shoes that press there, and sometimes with a bony bump.

The difference matters for the exercises you do: people with insertional pain usually avoid dropping the heel below the level of a step early on.^[6]

What helps

• A progressive loading program. Clinical guidelines for midportion Achilles tendinopathy are built around exercise.^[3] Both eccentric heel drops and heavy, slow resistance training work; in a head-to-head trial the results were the same at a year, and people were more likely to stick with the heavy, slow program.^[4] Our guide to Achilles heel-drop exercises shows how.
• Adjust, don’t stop, running. Use the pain as a guide: mild discomfort during a run (say 3 out of 10 or less) that settles by the next morning is usually acceptable. Cut hills and speed first, and go back to flatter, easier running.
• Calf strength and flexibility, and a look at your shoes. A small heel lift can take pressure off an irritated tendon for a while.

What doesn’t help much

• Complete rest lets the tendon lose capacity, and pain often returns when running resumes.
• Injections. A Cochrane review found little evidence that injection therapies improve function for Achilles tendinopathy,^[7] and platelet-rich plasma was no better than placebo in randomized trials.^[8,9]

When to get help

If a few weeks of adjusted training and exercises aren’t making progress, an evaluation helps. We confirm the diagnosis (sometimes with ultrasound at the practice), check your running and shoes, and build a plan. For insertional pain that won’t settle, shockwave therapy has good evidence.^[10] See our Achilles tendon page and sports medicine.

When to see a podiatrist