Photo by RUN 4 FFWPU on Pexels
Plantar fasciitis is one of the most common and frustrating running injuries. The characteristic stabbing heel pain — worst first thing in the morning, or after sitting for a long time — is immediately recognisable to anyone who has had it.
What makes it particularly frustrating is that it responds poorly to rest alone, and many runners deal with it recurring for months or even years. Understanding the mechanism explains why, and what actually works.
What Is the Plantar Fascia?
The plantar fascia is a thick band of connective tissue (fascia) running along the underside of the foot, from the heel bone (calcaneus) to the base of the toes. It acts as a spring during running, absorbing and releasing energy with each foot strike.
Plantar fasciitis is degeneration and irritation of this tissue, typically where it attaches to the heel bone. Despite the “-itis” suffix, research suggests it’s primarily a degenerative condition (like tendinopathy) rather than an acute inflammatory process — which is why anti-inflammatory approaches (ibuprofen, ice) provide only partial relief.
Causes
Load exceeding recovery capacity: The most common cause is simply doing too much too fast — a sudden increase in weekly mileage, adding speedwork, or switching to a race with lots of running before the plantar fascia has adapted.
Calf and Achilles tightness: The calf muscles, Achilles tendon, and plantar fascia form a continuous kinetic chain. Tight calves reduce ankle dorsiflexion and transfer load to the plantar fascia with each step.
Foot strike pattern: Runners who heel-strike heavily put more load on the plantar fascia insertion point at the heel. Not everyone who heel-strikes gets plantar fasciitis, but it’s a risk factor.
Increased time on feet: Changes in daily activity (starting a job that requires standing all day, moving to a new city and walking more) can trigger it even without increased running.
Footwear: Running in worn-out shoes (degraded midsole cushioning), transitioning too quickly to minimalist footwear, or training in very flat shoes without adequate heel cushioning can all contribute.
Intrinsic foot muscle weakness: The small muscles of the foot support the arch dynamically. Weakness here increases load on the plantar fascia.
Symptoms
- Sharp heel pain, worse first thing in the morning — the plantar fascia shortens during sleep; the first steps stretch it acutely, causing pain
- Pain after sitting or inactivity that improves with movement (only to return after sustained activity)
- Pain along the underside of the foot, typically at or near the heel
- Pain that worsens after (not during) runs — mild cases may feel fine while running but painful afterward
Treatment
Plantar fasciitis is notoriously slow to resolve — most cases take 6–18 months without appropriate management. With the right treatment, this can be reduced significantly.
The most evidence-backed interventions:
1. Plantar fascia and calf stretching
The two most impactful stretches:
Plantar fascia stretch (first thing in the morning, before getting out of bed): Sit on the edge of the bed. Cross the affected foot over the other knee. Pull the toes back toward the shin until you feel a stretch in the arch of the foot. Hold 30 seconds. Repeat 10 times. Do this before taking your first steps.
Calf stretches: Both gastrocnemius (straight knee) and soleus (bent knee) need to be addressed:
– Gastrocnemius: Stand facing a wall, affected leg behind you, heel on the floor. Lean into the wall until you feel a stretch in the calf. Hold 30 seconds, 3 repetitions.
– Soleus: Same position but bend the back knee slightly. Hold 30 seconds, 3 repetitions.
2. Eccentric heel drops
Stand on the edge of a step, affected foot only. Rise onto the ball of the foot, then lower the heel below the step level slowly (4–5 second count). Use the other foot to rise; only the affected foot to lower.
3 × 15 repetitions, twice daily. This is the most evidence-backed exercise for plantar fasciitis and Achilles tendinopathy. It hurts initially — some discomfort during the exercise is expected and acceptable.
3. Load management
Reduce running to a level that doesn’t worsen symptoms significantly. This doesn’t necessarily mean stopping running entirely — many runners can continue at reduced volume and intensity while managing plantar fasciitis.
Avoid barefoot walking at home on hard floors — a common aggravating factor. Wear supportive shoes or orthotic sandals (e.g., Birkenstock) from the moment you get out of bed.
4. Night splint
A night splint holds the foot in dorsiflexion (toes pulled toward shin) during sleep, preventing the plantar fascia from contracting overnight. This dramatically reduces morning pain for many people with plantar fasciitis. Available from pharmacies and online — used for 4–8 weeks.
5. Heel cushion or orthotic insole
Temporary heel cups (gel or silicone, available in pharmacies) reduce load on the heel insertion point. Custom orthotics from a podiatrist are worth considering for persistent cases or if you have significant foot structural issues.
What Doesn’t Work (or Works Less Than Commonly Thought)
Rest alone: Complete rest reduces symptoms temporarily but doesn’t address the degenerative tissue — return to running brings the pain back. Graduated loading combined with rehabilitation is more effective.
Ice: Reduces pain temporarily but doesn’t address the root cause (this is a degenerative, not inflammatory, condition primarily).
Cortisone injections: Can provide short-term pain relief but may weaken the plantar fascia tissue and do not address the underlying cause. Used as a temporary measure, not a cure.
Foam rolling the plantar fascia: Provides temporary symptom relief. Using a frozen water bottle or lacrosse ball under the foot can reduce discomfort. Not a curative intervention.
Return to Running
Return when:
– Morning pain has resolved or is minimal
– The eccentric heel drop exercise can be completed without significant pain
– Walking for 60 minutes doesn’t worsen symptoms
Return gradually — start with 15–20 minute runs on soft surfaces. Increase by 10% per week maximum. Avoid speedwork and intervals for the first 4–6 weeks back.
Prevention
Once resolved:
– Maintain calf stretching daily (plantar fascia stretching and calf stretches take 5 minutes — a permanent addition to the morning routine)
– Don’t increase weekly mileage by more than 10%
– Replace running shoes every 500–800km — degraded cushioning increases plantar fascia load
– Continue eccentric heel drops 3 times per week as maintenance
When to See a Professional
See a GP, physiotherapist, or podiatrist if:
– Symptoms haven’t improved after 6–8 weeks of the above management
– Pain is significant during normal walking
– Swelling, bruising, or sudden worsening of pain (may indicate a plantar fascia tear)
Physiotherapy often includes shockwave therapy for persistent cases — strong evidence supports its effectiveness for plantar fasciitis that hasn’t responded to conservative management.
Summary
Plantar fasciitis responds to a consistent rehabilitation programme, not rest:
- Stretch the plantar fascia before getting out of bed — 10 × 30-second stretches first thing in the morning
- Eccentric heel drops daily — the most evidence-backed exercise for recovery; some discomfort is expected
- Wear supportive shoes at all times including at home — avoid barefoot walking on hard floors
- Use a night splint for the first 4–8 weeks — reduces morning pain significantly by preventing overnight shortening
- Continue maintenance stretching after recovery — plantar fasciitis recurs without consistent calf and arch maintenance
Next read: Running with knee pain: causes and solutions