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Running insoles (also called orthotics or footbeds) are inserts placed inside your running shoe to modify the way your foot sits, functions, or is supported. The claims made for them range from modest (better comfort) to ambitious (improved performance, injury prevention). The evidence is more nuanced.
What Running Insoles Actually Do
A running insole can modify several aspects of how your foot interacts with the shoe:
- Arch support: Raise or support the arch, reducing the degree of pronation (inward rolling of the foot)
- Cushioning: Add shock absorption beyond what the shoe midsole provides
- Heel cup: Stabilise the heel and reduce lateral movement
- Forefoot support: Change the angle of the forefoot relative to the rear foot
- Volume fill: Simply take up space in a shoe that’s too wide or too high-volume for your foot
The clinical distinction matters: insoles that correct a genuine biomechanical issue produce measurable results; insoles used “just in case” on an otherwise well-functioning foot produce minimal benefit and occasionally cause problems.
When Insoles Are Genuinely Useful
Overpronation: If your foot rolls significantly inward when running, insoles with medial arch support can reduce the degree of rotation. This is most relevant for runners who experience knee tracking problems (runner’s knee/PFPS), shin splints, or plantar fasciitis linked to overpronation.
Plantar fasciitis: Insoles with good arch support and heel cushioning are a standard part of the management protocol for plantar fasciitis — they offload the plantar fascia by supporting the arch and reducing the strain on the tissue during each footstrike.
Leg length discrepancy: A genuine leg length difference (even small ones of 5–10mm) can create compensatory movement patterns that lead to hip, knee, or lower back pain. A heel lift on the shorter side is a simple and effective intervention.
Flat feet (fallen arches): Runners with very low arches (hyperpronation) often benefit from structured arch support, which reduces the degree of inward collapse.
When Insoles Are Less Likely to Help
Neutral running gait: If your running gait is mechanically efficient and you have no recurring injury pattern, there’s limited evidence that insoles improve anything. Well-fitting shoes with adequate cushioning do the job.
Performance improvement: The evidence for insoles improving running economy or speed in healthy runners is weak. The main performance-related use is if an insole corrects a problem that was consuming energy (e.g., excessive pronation requiring compensatory muscular control).
Types of Insoles
Off-the-shelf (OTC) insoles: Ready-made insoles available from running shops, chemists, and online. Brands like Superfeet, Sorbothane, and Sidas offer arch-support and cushioning variants at £20–60. These are appropriate for mild biomechanical issues and for runners who want more cushioning than their shoe provides.
Custom orthotics: Made from a cast or scan of your foot by a podiatrist or orthotist. Cost significantly more (£150–400+) and are appropriate for significant biomechanical issues or when OTC insoles haven’t resolved a persistent problem.
Research context: Studies comparing custom orthotics to high-quality OTC insoles have found similar outcomes for many common running injuries — custom orthotics aren’t automatically better.
The Footwear First Principle
Before considering insoles, it’s worth checking whether your running shoes are appropriate for your foot type:
- If you have a high arch, neutral or cushioned shoes are appropriate
- If you have flat feet or significant overpronation, stability or motion control shoes may already provide the support needed
- If your shoes are old and the midsole is compressed, new shoes may resolve the problem without insoles
A gait analysis at a specialist running shop (most offer this free) is a useful starting point — it identifies whether your foot mechanics need correction and whether the shoe or an insole is the right solution.
Insoles and Injury Prevention: What the Research Says
The evidence base for insoles reducing injury rates is mixed:
- Plantar fasciitis: Strong evidence that arch-supporting insoles reduce pain and aid recovery
- Shin splints: Moderate evidence that shock-absorbing insoles reduce the incidence of medial tibial stress syndrome, particularly for military recruits with high running loads
- Runner’s knee: Evidence is mixed — hip and glute strengthening shows stronger results than insoles alone
- Stress fractures: Some evidence that cushioning insoles reduce bone stress, particularly in high-volume training
The strongest conclusion from the research: insoles are a useful part of injury management for specific conditions rather than a universal injury prevention tool.
Summary
Running insoles can be genuinely helpful — for the right runner and the right problem:
- Get a gait analysis first — at a running shop, for free — before spending money on insoles
- OTC insoles are appropriate for most mild issues — custom orthotics are warranted only for significant biomechanical problems or when OTC options haven’t worked
- Insoles help most with plantar fasciitis and overpronation-related injuries — the evidence is strongest here
- New, well-fitting shoes may solve the problem before insoles become necessary
- Insoles don’t replace strengthening work — hip, glute, and calf strength address the root causes of most running injuries more effectively than passive support
Next read: How to prevent shin splints when running