Why your Achilles pain keeps coming back

Most people with Achilles pain follow the same pattern: rest until it stops hurting, return to activity, pain comes back within two weeks. The cycle repeats for months, sometimes years. The reason is simple, rest reduces pain sensitivity but does not restore tendon capacity.

The Achilles tendon does not heal passively. It remodels under load. When you remove the load, you remove the stimulus for adaptation. The tendon becomes less reactive (which feels like improvement) but no stronger. The first time you ask it to perform again, it is in the same state it was before you rested.

The older term is tendinitis, implying inflammation. Anti-inflammatories, rest, and ice are the logical treatments for inflammation. The problem is that most chronic Achilles pain involves no inflammatory cells at biopsy. The tendon tissue is disorganised, not inflamed. This is tendinopathy.

Treating tendinopathy like tendinitis produces short-term relief and long-term recurrence. Anti-inflammatories reduce pain without addressing the tissue quality. Rest removes load without rebuilding capacity. The tendon is still disorganised when you return to activity.

Tendon collagen remodels through mechanical stress. The stimulus that drives adaptation is load, specifically, progressive load with adequate recovery time. The tendon needs to be loaded, overloaded slightly, and allowed to repair. The repair response produces stronger, better-organised collagen.

This is the principle behind heavy slow resistance training for Achilles tendinopathy. Slow tempo (3 seconds up, 3 seconds hold, 3 seconds down), substantial load, twice daily. Not running. Not explosive. Slow, controlled, progressive.

Where on the tendon the pain sits changes the treatment. Mid-portion (2–6cm above the heel) tolerates the heavy slow resistance protocol well. Insertional (at the heel bone) is more sensitive to compressive load, activities that compress the tendon against the heel bone, including stretching into dorsiflexion, often make it worse.

Treating insertional tendinopathy with the same protocol as mid-portion frequently aggravates it. The assessment should confirm which presentation you have before any loading programme begins.

If your Achilles pain has been present for more than 6 weeks, has not responded to load modification, or if you are unsure whether it is mid-portion or insertional, a clinical assessment is the appropriate next step. A movement screen, strength test, and palpation will determine the presentation and guide the protocol.