Knee Pain After Running: Causes, What Helps, and When to See a Physio

Knee pain is the most common complaint among runners. Most of it is an overload problem rather than damage: the knee, or the tissues around it, have been asked to do more than they were ready for. The good news is that most running knee pain improves with the right changes. This guide covers the usual causes, what to do first, and when you need a professional to look at it.

Important: this article is general information, not a diagnosis. If your pain is severe, your knee is swollen, or you cannot put weight on it, see a GP.

When to get help straight away

The NHS advises getting urgent help if you cannot move your knee or put weight on it, if it is badly swollen or has changed shape, if it locks or gives way, or if you have a high temperature with redness or heat around the knee. Do not run through any of these.

Where does it hurt? Common causes by location

Around or behind the kneecap: runner's knee

Patellofemoral pain, usually called runner's knee, is a dull ache around or behind the kneecap. It often gets worse on stairs, downhill, squatting, or after sitting for a long time with bent knees. It is commonly linked to a jump in mileage or hills, and to weakness in the hips and thighs.

On the outside of the knee: IT band syndrome

A sharp or burning pain on the outside of the knee that often starts at a predictable point into a run and makes you stop. It is common in runners who have increased distance quickly or do a lot of cambered roads or downhills.

Just below the kneecap: patellar tendon pain

Pain at the bottom of the kneecap, often stiff at the start of a run and when jumping or going downstairs. Tendons respond slowly; they generally need gradual loading rather than complete rest.

On the inside of the knee

Pain on the inner knee can have several causes, from tendon irritation to the meniscus. If it persists, clicks or catches, get it assessed.

What to do first

• Reduce the load. Cut mileage and remove hills and speed work. Cross-training that does not hurt, like cycling or swimming, keeps your fitness.
• Ice for comfort. A bag of frozen peas wrapped in a damp tea towel for up to 20 minutes can ease pain. Never put ice directly on skin.
• Do not run through pain. The NHS guidance for runners is to stop running and see a GP or physiotherapist if knee pain has not gone after a week.

What usually fixes it

• Strength work. Most running knee problems improve with strength in the quads, glutes and hips: squats, step-ups, split squats, bridges and side-lying leg raises, built up gradually. A physio can tailor this.
• Smarter load. Increase weekly mileage gradually, and avoid adding distance, hills and speed at the same time.
• Check your shoes. Very worn shoes, or a sudden change of shoe type, can contribute.
• Look at cadence. A slightly quicker, shorter stride reduces load at the knee for some runners. Change it gradually.

For the prevention side, read preventing common running injuries and how runners can protect their joints.

Do joint supplements help knee pain?

We will be straight with you: no supplement treats knee pain, and you should be wary of any product that claims to. Load management, strength and professional advice come first.

What nutrition can do is support normal joint and connective-tissue structure over the long term. Vitamin C contributes to normal collagen formation for the normal function of cartilage, and manganese contributes to the normal formation of connective tissue. Many runners also take glucosamine and chondroitin; the research on those is mixed, as we explain in do joint supplements work for runners? Runner Joint Support contains glucosamine, chondroitin, vitamin C and manganese as part of a long-term routine for high-mileage runners, not as a fix for an injury.

FAQs

Should I stop running if my knee hurts?

If the pain is more than mild, or is getting worse, yes. Rest from running and cross-train. If it has not settled after a week, see a GP or physio.

Is knee pain after running normal?

Mild aches after a big increase in training are common. Pain that changes how you run, lingers, or comes with swelling is not normal.

Can I keep training for my marathon?

Often yes, with modified training, but get it assessed early. A week off now is better than missing the race.

This article is general information and not a substitute for medical advice. Food supplements should not be used as a substitute for a varied, balanced diet and healthy lifestyle.