A runner with a sore heel is told “plantar fasciitis” almost by reflex, and often that is right. But the heel is a small area with several structures in it, and the correct response ranges from “reduce your volume about twenty per cent and keep going” to “stop running now and get imaged”. Guessing wrong in the second case is the one genuinely costly mistake available in this subject.

Three questions separate almost all of it: what the pain does during a run, where exactly it sits, and what it does on the first steps in the morning.

The question that matters most

The map for runners

The pattern that means stop today

What actually causes it

Heel injuries in runners are load problems, and load has more inputs than weekly mileage. When a heel flares, one of these usually changed in the preceding month.

• A volume or intensity jump. The classic. Tissue adapts more slowly than fitness improves, so the fortnight where running felt easy and you added a lot is usually the fortnight that caused this.
• New shoes, or old ones. A drop change of even a few millimetres shifts load between the fascia and the Achilles — lower drop loads the Achilles more, higher drop loads the fascia more. A midsole with several hundred miles on it has lost the cushioning you are counting on.
• Racing shoes used for training. Thin, stiff, plated shoes concentrate load and are not built for daily volume.
• A surface change. Treadmill to road, grass to track, or the same cambered side of the road every day.
• Hills and speed added together. Both load the Achilles insertion hard. Introduced in the same block, they are a common cause of back-of-heel pain.
• Calf capacity that has not kept up. The most under-appreciated one. The calf and Achilles absorb an enormous share of running load, and a runner who never does resistance work is asking a small tissue to do a large job.

What to change, in order

1. Work out which pattern you have first. Everything below depends on it, and the bone pattern exits this list immediately and goes to an examination.
2. Reduce rather than stop. For fascia and tendon problems, complete rest feels productive and disappoints: the pain settles, nothing about the tissue’s capacity changes, and it returns within a fortnight of resuming. Find the volume that does not leave the heel worse the following morning and run that.
3. Use the next-day test. Mild discomfort during a run that is gone by the next morning is acceptable. Pain that is worse the next day means the last run was too much, whatever it felt like at the time.
4. Load the calf deliberately. Heavy, slow calf raises — straight-leg and bent-knee — two or three times a week. For midportion Achilles problems this is the treatment rather than an adjunct. Build capacity while you reduce running, and you come back to a tissue that can take more than it could before.
5. Fix the shoe before buying an insert. Replace a midsole that is done. If the pain is at the back of the heel, a small heel lift in both shoes takes tension off the insertion immediately and costs almost nothing.
6. Change one variable at a time. Runners commonly change shoes, add orthotics, start stretching and cut mileage in the same week, then learn nothing about which of them mattered.
7. Rebuild gradually and keep the strength work. Return over weeks rather than days, and do not drop the calf loading the moment it stops hurting — that is what prevents the next one.

Running with plantar fasciitis

Most runners with plantar fasciitis can keep running at a reduced dose. The rules that stop it dragging on:

1. Use the next-morning test. If the first steps the next morning are no worse, the run was within what the fascia can take. If they are worse, cut the next run.
2. Cut volume and intensity first. Shorter and easier runs; drop speed work and hills until the mornings are settling.
3. Stretch the fascia before your first steps every morning, and do the heel-raise strength work on non-running days.
4. Keep the shoes supportive, including off the run. A worn midsole or flat shoes at home undo a lot.
5. Tape for long runs if it helps: low-Dye or KT tape can take the edge off for a few hours.
6. Stop if the pattern changes. Pain that builds through the run, or hurts when the heel is squeezed, is not plantar fasciitis behaviour. See the bone pattern above.

Full exercise dosing is on the plantar fasciitis stretches and exercises page, and the Achilles version on Achilles tendonitis exercises.

Can I keep running?

For plantar fasciitis and most tendinopathy, usually yes, at reduced volume, provided the heel is not worse the next morning. Many runners get through it without a full break.

For a bone stress injury, no — and this is the distinction the whole page exists to make. For nerve entrapment it depends on what is compressing the nerve; adding a firmer orthotic, which is the instinct, sometimes makes it worse.

Common questions

Should I stretch before running?

Static stretching immediately before a run has little to offer and may reduce power briefly. What helps is a gradual warm-up, and calf and fascia work done as its own session rather than squeezed in at the start. One caution: if the pain is right on the bone at the back of the heel, deep calf stretching off a step compresses exactly the tissue that hurts. In that case, stop doing it.

Do I need custom orthotics?

Usually not as a first step. A good over-the-counter insert answers the question of whether support helps for a fraction of the cost, and for most runners it is as effective. Custom devices earn their place in a foot with an unusual structure, or where a well-fitted off-the-shelf option has genuinely been tried and failed. Note too that a tall, rigid arch can aggravate nerve-type heel pain.

Is it the carbon-plated shoes?

They can contribute, particularly when used for volume rather than for racing. Plated shoes change how the foot and ankle are loaded and shift work around the calf and Achilles. If heel pain appeared in the block where those shoes became your daily trainer, that is worth treating as the likely variable.

How long until I can race again?

For fasciitis and tendinopathy, think in months for full resolution but often only weeks before useful training resumes at reduced load. For a calcaneal stress fracture, typically six to twelve weeks before comfortable walking, then a graded return to impact after that. The honest answer in both cases is that it depends far more on how early you responded than on what you do afterwards.

Can I cross-train?

Yes, and you should. Cycling, swimming, pool running and upper-body work maintain fitness without asking anything of the heel. Losing condition is not a required part of recovery, and runners who keep training in some form tend to make better decisions about when to resume, because they are less desperate to.

Further reading

• Heel pain by location — the full map, if you are not sure which of these you have.
• Calcaneal stress fracture — the one that gets worse with activity, in detail.
• Achilles tendonitis — why midportion and insertional need different exercises.
• The treatment ladder — what to do first, second and last.
• Shoes, inserts and kit — how to judge what gets sold for heel pain.
• Achilles tendonitis exercises — both loading programmes, with a printable sheet.
• Back of heel pain — every cause at the back of the heel, side by side.

• Koc TA, et al. Heel Pain – Plantar Fasciitis: Revision 2023. Clinical Practice Guidelines, Journal of Orthopaedic & Sports Physical Therapy.
• Bergman R, Kaiser K. Stress Reaction and Fractures. StatPearls, NCBI Bookshelf.
• Allam AE, Chang KV. Plantar Heel Pain. StatPearls, NCBI Bookshelf.
• American Academy of Orthopaedic Surgeons, OrthoInfo. Heel Pain.