Updated: May 27
Someone recently emailed us to ask whether they should do their Achilles tendon rehab exercises until they are totally fatigued. How hard to push during your workouts for your injured Achilles tendon depends on a few factors, which this article will explain. Remember, if you need more help with an Achilles injury, you're welcome to consult one of our team via video call.
The terms tendinitis, tendonitis, tendinosis, and tendinopathy mean the same thing for all practical purposes, and we use these interchangeably in our articles.
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Don’t push into fatigue with a painful Achilles tendon
Anyone who has watched videos or read about Achilles tendon rehab would likely have come across the advice that you really need to work the tendon hard, usually with exercises that involve quite heavy weights, to get it strong again.
Now this is true, but you have to introduce the exercises and increase their difficulty gradually to get your tendon used to them. If you go at it too hard from the start, i.e. do your exercises until you are exhausted, you run the risk of overloading your tendon and making your pain worse.
How hard you can push will depend to a large extent on how sensitive or irritable your tendon is.
Painful tendon: Establish a baseline and build on that
Injured tendons often have a delayed pain response. They may feel absolutely fine while you’re doing your exercises but then start to hurt more several hours later. If your tendon is in the very irritable stage, it usually also doesn’t take much to cause the pain to flare up quite significantly. Flare-ups can be really demoralising, forcing you to rest and start again.
So, when establishing your baseline, it is always best to test a much smaller dose of exercises than what you think you should be able to do and then monitor your 24-hour symptom response.
Slight pain or discomfort while or after doing your exercises is OK and expected, but you don’t want anything with an intensity that you would rate as more than 3 out of 10. If your tendon is a bit more sensitive after doing the exercises, that extra sensitivity also has to settle down within 24 hours.
If your tendon tolerated the session well and the exercises felt easy to complete, you can then usually increase the number of repetitions or the weight (your physio will guide you with this) slightly. When you reach a point where either the exercise set feels quite hard to complete with good form or it is on the verge of significantly increasing your pain, this is usually your baseline.
Once we've established that baseline of how many, say, heel raises with a certain weight the tendon can tolerate, we’ll get the patient to train at that level until they are used to it and ready to gradually add repetitions or weight once again, keeping the rehab programme in the sub-3-out-of-10 pain range.
So, for very painful or sensitive tendons, the 24-hour symptom response determines the progression rather than the level of fatigue.
Tendon not painful: Push hard but not all the way
If the patient has a tendon that doesn’t get irritated easily and they don't experience frequent flare-ups, then we tell them that they can use fatigue as a guideline for how hard to push.
We usually advise them to work into fatigue, but still hold back a tiny bit to test the first few sessions.
All of us who have done endurance or strength training when uninjured know that feeling when you’re already quite tired towards the end of a session, and then you force yourself to push out the last few laps or reps so that you can get that feeling of, “Phew! That was a good, hard, workout!”
We don’t want our Achilles patients to go there during the early stages with their rehab exercises.
They might do that during the later stages of their rehab or once we've properly tested how their tendon reacts to more intense training sessions. But when we're not sure yet how the injured tendon is going to react, it's better for them to feel that they’ve worked hard, but to stop short of having to force themselves to continue.
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.
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.
About the Author
Van Der Vlist, A. C., et al. (2021). "Which treatment is most effective for patients with Achilles tendinopathy? A living systematic review with network meta-analysis of 29 randomised controlled trials." British Journal of Sports Medicine 55(5): 249-256.