Knee Pain While Running: Causes, Fixes, and When to Stop

Knee Pain Is Not Normal. But It Is Common.

Most runners encounter knee pain at some point. The important distinction: common does not mean acceptable, and knee pain is not something you run through and hope disappears. It is your body telling you something specific is wrong. The question is which specific thing.

Here are the three most common causes of knee pain in runners, how to identify each one, and what to actually do about it.

1. Runner's Knee (Patellofemoral Pain Syndrome)

**Where it hurts:** Around or behind the kneecap, especially when going down stairs, after long runs, or after sitting for extended periods.

**What causes it:** Weak quadriceps and hip abductors allow the kneecap to track incorrectly. The kneecap rubs against the femur instead of gliding over it cleanly. Overstriding — landing with your foot far ahead of your body — makes this worse.

**How to fix it:**

• Strengthen your glutes and hip abductors: clamshells, side-lying leg raises, single-leg squats
• Reduce your stride length slightly and increase cadence by 5-10 steps per minute
• Avoid downhill running until pain resolves
• Ice after runs if inflamed
• Reduce weekly mileage by 30-40% for 2 weeks while you build strength

**Can you run through it?** Short answer: reduced and careful running is usually fine if the pain is mild (2/10 or below). Sharp or worsening pain means stop.

2. IT Band Syndrome

**Where it hurts:** Outer knee, often described as a sharp or burning sensation that begins after a consistent distance — say, every run after kilometre 6. The pain is very localisable to the outside of the knee.

**What causes it:** The iliotibial band — a thick band of connective tissue running from hip to shin — tightens and rubs against the outer edge of the knee. Weak glutes, excessive hip drop while running, and ramping up mileage too quickly are the main culprits.

**How to fix it:**

• Foam roll the outer thigh (not the IT band itself — it doesn't respond to direct compression)
• Strengthen the glutes: glute bridges, single-leg deadlifts, lateral band walks
• Temporarily reduce mileage and avoid running the distance at which pain begins
• Address hip drop with running form drills

**Can you run through it?** IT band syndrome worsens with continued running. Take some time off from running and use it to strengthen the hips. Runners who ignore this typically end up sidelined for much longer than if they had addressed it early.

3. Patellar Tendinopathy (Jumper's Knee)

**Where it hurts:** The tendon just below the kneecap. Pain is usually sharp on palpation and comes on with loading — going up stairs, squatting, landing.

**What causes it:** Repetitive loading of the patellar tendon without adequate recovery. Common in runners who increase speed work or race frequency too quickly. Also common in runners who do heavy leg sessions at the gym without understanding how to manage tendon loading.

**How to fix it:**

• **Isometric exercises are the immediate fix:** Single-leg wall sit, held for 45 seconds, 4 sets. This reduces tendon pain acutely and is backed by solid research.
• Progress to slow, heavy single-leg squats as the tendon responds
• Avoid complete rest — tendons need load to heal, just controlled load
• Modify training: fewer speed sessions, no back-to-back hard days

**Can you run through it?** Tendinopathy is a spectrum. Mild tendinopathy can be managed with load modification. Ignore it for months and you risk a partial tear.

When to See a Doctor

See a sports medicine doctor or physiotherapist if:

• Pain is 5/10 or above during running
• Pain persists beyond 2 weeks despite rest and strengthening
• The knee is visibly swollen
• You cannot walk without a limp

Do not see a general practitioner for running injuries unless they specifically have a sports medicine background. The advice to "just rest for a few weeks" without addressing the cause solves nothing.

The Real Root Cause

In our experience at Runpundit, the vast majority of knee pain in runners has the same underlying cause: weak glutes. Glutes are the primary stabilisers of the entire lower limb. When they are weak, the knee compensates. Strength work — 2 sessions of 20 minutes per week — is not optional for distance runners. It is insurance.

Several athletes who came to us with chronic knee pain and were told to stop running are now pain-free and racing half marathons. The fix was not rest. It was targeted strength work and form correction.