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Can I run a marathon with Achilles tendonitis?

Updated: May 27, 2023

In this article, I’ll be discussing whether or not you can run a marathon with Achilles tendonitis. We’ll look at case studies of actual Achilles tendonitis patients of mine who attempted to run a marathon while injured to give you an idea whether the answer to this question might be a “yes” or a “no” for you. Remember, if you need more help with an Achilles injury, you're welcome to consult one of our team via video call.

Learn about the risks associated when running a marathon with Achilles tendonitis.

The terms tendinitis, tendonitis, tendinosis, and tendinopathy mean the same thing for all practical purposes, and we use these interchangeably in our articles.

In this article:

We've also made a video about this:

Achilles tendon overview

Let’s start with a brief overview of the Achilles tendon and Achilles tendonitis. We have a wealth of detailed information about this in our blog, in our Achilles Pain Fact File, and on our Treat My Achilles YouTube Channel.

The job of the Achilles tendon is to attach your calf muscles to the back of your heel bone. Your calf muscles contract to produce power and movement at the ankle, and the Achilles is like a rope that transfers that force to move the joint.

The anatomy of the Achilles tendon and calf

A healthy body is regenerating tissue all the time – breaking down old tissue and laying down new stuff. When we train, the body lays down the new tissue stronger than it was before, and as a result we get stronger and fitter. However, if there’s not enough recovery time after high-demand training sessions, that regeneration process can get disrupted, leading to overload of the tendon and overuse injuries such as Achilles tendonitis.

There are different stages of Achilles tendonitis, and the rehab programmes of these are all slightly different, with different exercises and strategies:

  • Acute/reactive: Brand new injury, tendon is thick/swollen, sensitive, sore.

  • Dysrepair: Pain and symptoms have been grumbling for a few weeks or more, it worsens or improves depending on activity.

  • Degenerative: Chronic Achilles pain, tendon is in a poor condition.

The demands of running a marathon

Depending on your stride length, you will take between 25,000 and 50,000 steps when you run a marathon!

Breaking down every step into its mechanical demands on your Achilles tendon, there’s a landing that absorbs forces equal to 6 to 12 times your bodyweight in ground reaction force (depending on which research you consult), and a push off with your whole bodyweight against gravity.

That’s an awful lot of cumulative load – imagine doing 1 set of 12,000 to 25,000 calf raises!

So … Can I run a marathon with Achilles tendonitis?

Everyone’s case is different, so I would always suggest that you get a health professional, preferably one who is experienced in treating runners, to assess your situation and give you the right advice.

However, I can give you two examples of patients I have seen with Achilles pain. One completed their marathon and even got a personal best; the other had to pull out of the race.

Whether or not you can run a marathon with Achilles tendonitis will depend on your specific case and circumstances.
Whether or not you can run a marathon with Achilles tendonitis will depend on your specific case and circumstances.

Case 1

The situation at three weeks until race day:

  • Very mild Achilles pain towards the end of longer training runs: 2 to 3 out of 10 pain with some mild stiffness afterwards.

  • Better by the following morning – no pain.

  • No pain caused by heel raises.

  • No pain caused by hopping.

This patient tapered their training and completed the marathon without any problems on the day. This is likely because the tendon was just about coping with the training, and the pain was just letting the runner know that the Achilles tendon was fatigued towards the end of the longer runs.

However, the taper in the last two weeks before the marathon allowed enough recovery time for the tendon to rebuild stronger than it was before, and therefore the race was OK in the end.

Case 2

The situation at three weeks until race day:

  • Achilles tendon sore every morning for at least half an hour – hobbling and unable to walk “normally” until it had “warmed up”.

  • Mild pain when walking around the house.

  • Painful to do a single-leg heel raise.

  • Painful to hop.

  • Very painful tendon at the start of a training run, then it would ease off for a while, then pain would return further into the run and steadily worsen.

  • The time until the onset of pain was getting shorter and shorter with each run as the injury was getting worse week-on-week.

For this patient, there was not enough time to sufficiently offload the tendon to allow for enough recovery and rehab before race day. Their tendon was in a state of dysrepair and was going to take months to fully recover.

This patient had raised a lot of charity money to take part and wanted to attempt the race anyway, fully knowing the risk. However, they had to pull out during the race as the pain was too severe, and they were unable to complete it.

What is the risk of rupturing my injured Achilles tendon during the marathon?

The biggest concern for most people considering running a marathon with an injured Achilles tendon is the thought of fully rupturing it during the race.

The good news for runners is that a rupture is far more likely to happen in “explosive” and multi-sprint sports such as basketball, soccer/football, and racquet sports. In one study looking at the sports-related incidence of Achilles rupture in the USA, running, hiking, and stretching were grouped together and made up 6% of the total incidence, whereas basketball alone made up 43%.

Explosive sports e.g. basketball carries a higher risk for Achilles tendon ruptures than running.
Explosive sports e.g. basketball carries a higher risk for Achilles tendon ruptures than running.

However, there are some factors that can increase the risk of Achilles tendon rupture while running a marathon:

  • Fluroquinolone antibiotics. This is a very specific type of antibiotic with a side effect that weakens tendons. Other antibiotics do not have this side effect, so it does depend on what has been prescribed for you.

  • Steroid injections into the Achilles tendon. These are good at calming down pain but bad for tendons in the long run.

  • Anabolic steroids.

Most Achilles tendon ruptures happen without pre-disposing symptoms, so it’s very difficult to avoid all risk. However, a very degenerative tendon that has been symptomatic for quite some time does run the risk of being structurally weaker and therefore easier to injure – hence why these injuries should be managed appropriately.

What’s more relevant to know for most people is that the longer you avoid dealing with an injury like Achilles tendonitis, the longer it takes to get better when you do start with rehab. So, if you’re struggling, don’t wait for months before consulting someone, get it on the right track as quickly as possible!

How we can help

Need more help with your Achilles injury? You’re welcome to consult one of the team at TMA online via video call for an assessment of your injury and a tailored treatment plan.

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We're all UK Chartered Physiotherapists with Master’s Degrees related to Sports & Exercise Medicine. But at Treat My Achilles we don't just value qualifications; all of us also have a wealth of experience working with athletes across a broad variety of sports, ranging from recreationally active people to professional athletes. You can meet the team here.

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About the Author

Steph Davies is a chartered physiotherapist with more than 15 years' experience and a Master’s Degree in Sports and Exercise Medicine. You can follow Steph on LinkedIn.


  1. Lemme NJ et al. (2018) Epidemiology of Achilles tendon ruptures in the United States: Athletic and non-athletic injuries from 2012 to 2016 Orthopaedic Journal of Sports Medicine 6 (11)

  2. Lorimer, Anna V., and Patria A. Hume. "Achilles tendon injury risk factors associated with running." Sports Medicine 44 (2014): 1459-1472.

  3. Purdam and Cook (2009) Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendonitis British Journal of Sports Medicine 43 (6): 409-416

  4. Rabello et al. (2020) Running a marathon – its influence on Achilles tendon structure Journal of Athletic Training 55 (2) 176-180

  5. Silbernagel, Karin Grävare, et al. "Continued sports activity, using a pain-monitoring model, during rehabilitation in patients with Achilles tendinopathy: a randomized controlled study." The American Journal of Sports Medicine 35.6 (2007): 897-906.


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