Achilles Tendon: Why does it flare back up when I return to running?

Getting back into running after a break can feel great at first. But then, after about four weeks, you might start to feel a sharp pain at the back of your heel. It hurts to walk or run. You rest for a week or two, and the pain gets better. But as soon as you start running again, the pain comes back.

This is likely Achilles tendinopathy, often caused by increasing your running intensity, duration, or frequency too quickly. Tendons can handle a lot of stress during activity, but pushing them beyond their capacity can lead to injury.

Other factors that increase the risk of Achilles tendinopathy include weak calf muscles, previous tendon issues, steroid use, age, sudden increases in training, and running on different surfaces.

If these risk factors aren't addressed, the pain will keep coming back. It's crucial to understand and manage these factors. You might have tried therapy and exercises without success. Maybe the exercises weren't challenging enough. For instance, running exerts forces on your tendons that are much greater than simple calf raises can replicate.

To recover properly, you need a gradual strengthening program tailored to your goal of running 5km. This program should assess and improve calf strength, as well as the flexibility and strength of other leg muscles. It should also address running technique and how you schedule your runs. Above all, remember that tendon healing takes time and patience.

If you're struggling with Achilles or any other tendon pain that just won't go away, it's best to see a physiotherapist. They can identify your specific risk factors and work with you to create a step-by-step plan to get you back to running pain-free.

Our articles are not designed to replace medical advice. If you have an injury or health concern, we recommend seeing a qualified health professional.

If you would like some further readings on achilles tendinopathy, please check out the following research articles:

Taunton et al. (2002) prevalence of common running injuries including Achilles tendinopathy

O’Neill et al. (2016) risk factors for Achilles tendinopathy

Nielsen et al. (2013) achilles tendinopathy may be linked to changes in training intensity or speed

McAuliffe et al. (2017) life impact of Achilles pain Silbernagel et al. (2007) and

Silbernagel et al. (2010) key papers on Achilles rehab and long term outcomes

Scott et al. (2015) great overview of factors influencing tendon health

Lyght et al. (2016) increasing step rate may reduce Achilles load