Why are we still saying “Running is bad for your knees”?

It’s one of those throwaway lines people repeat without thinking. Heard it in school. Read it in a tabloid. Mention a bit of knee pain, and someone will chime in with: “Ah well, running’s not great for your joints.”

But here’s the thing: the evidence says otherwise.

A Common Misunderstanding

Plenty of people worry that running wears out your knees. But that’s not what the research shows.

Large studies looking at recreational runners consistently find that they’re less likely to develop knee osteoarthritis than non-runners. Even people who run several times a week into middle age show no higher rates of wear-and-tear than those who don’t run at all. In fact, they may be better off.

Now, ultra-distance runners and elite-level athletes are a different story. The load they place on their joints is extreme, and long-term exposure at that level does carry more risk. But for the vast majority of people, running is not just safe—it’s likely beneficial.

So Why Do Knees Hurt?

Sometimes it’s load. A sudden jump in mileage. A return after time off. New shoes. A harder surface. Knees feel stiff or achy, and it’s easy to blame the run.

But pain doesn’t mean damage. Cartilage doesn’t just dissolve overnight. In fact, joint cartilage responds to moderate load in much the same way as muscle or bone: it adapts. It remodels. It gets stronger. MRI studies have shown that after a run, joint changes often return to baseline within hours or days. That’s recovery, not breakdown.

And when people do pick up an injury, the problem is rarely “too much running” in itself. It’s more often that tissues—tendons, joints, muscles—weren’t ready for the change. Unprepared muscles, poor pacing, or long-term deconditioning can all tip the balance. Add life stress, poor sleep, or limited strength work, and the load tolerance drops further.

But running? That’s not the villain.

What Running Offers

The upsides of regular running are huge. It boosts cardiovascular health, supports bone density, improves mood, lowers inflammation, and encourages joint movement—all protective factors for long-term knee health.

Running is weight-bearing, rhythmical, and efficient. It encourages full range of movement through the leg, engages the muscles that support the knee, and helps maintain functional independence with age. Not many forms of exercise tick that many boxes.

So instead of avoiding it, we need to be smarter about how we approach it.

How to Run Without Knee Trouble

1. Build gradually

Sudden spikes in distance or intensity are where trouble starts. A general guide is no more than a 10% increase in load each week—but more importantly, listen to your body.

2. Strength train regularly

Running alone doesn’t develop the strength needed to absorb impact efficiently. Training the hips, thighs, and calves helps buffer the joints and share the load.

3. Vary the pattern

Mix in different paces, terrains, and even activities. The more variation your body sees, the more resilient it becomes.

4. Don’t ignore early signs

A niggle isn’t a reason to panic, but it’s also not a reason to keep pushing through. Small adjustments early on—reducing volume, adding recovery, checking technique—can prevent longer lay-offs down the line.

In Summary

Running isn’t bad for your knees. In many cases, it’s one of the best things you can do for them.

What matters is how you train, how you recover, and how well your body is prepared for the task. The answer isn’t fear or avoidance. It’s knowledge, patience, and progression.