Hi everyone,

One of the most common things I hear in clinic (especially when people are trying to get active again) is:

• “Running is going to ruin my knees, right?”

• “My mate said my cartilage will ‘wear out’.”

• “If I run now, I’ll end up with arthritis later.”

So here’s the calm, evidence-based answer:

No — recreational running is not generally bad for your knees, and may even be protective.

The bigger risks tend to be very high-volume/elite running, running through fatigue, and running with prior injury + poor load management.

And if you hate running? No stress — we’ll finish with why walking might be the most underrated “anti-aging” habit you can do.

What the research shows (in plain English)

• Across systematic reviews and large cohorts, recreational running isn’t linked with higher knee OA compared with not running. (Dhillon et al., 2023; Lo et al., 2017; Alentorn-Geli et al., 2017; Timmins et al., 2017)

• In 3,804 marathon runners, years of running / marathons / weekly mileage weren’t associated with more hip or knee arthritis. (Hartwell et al., 2023)

• Even in people who already have knee OA, self-selected running did not worsen x-rays or pain, and runners had more pain improvement than non-runners in one large dataset. (Lo et al., 2018)

• MRI research suggests marathon training can show some reversible soft tissue/cartilage changes, while bone marrow lesions in key weight-bearing zones may improve. (Horga et al., 2019; Hartwell et al., 2023)

Bottom line: for most people, running is not “knee poison.” It’s a dose + context issue.

So what actually increases knee risk?

Across studies, the heavy hitters are usually:

• Age

• Higher BMI

• Prior knee injury or surgery

• Family history / genetics

…more than running volume itself. (Hartwell et al., 2023; Lo et al., 2018; Lo et al., 2017; Shen et al., 2024)

One factor I really want you to respect:

Running while fatigued

Running in a fatigued state increases knee joint forces and may increase overuse risk. (Van Middelaar et al., 2022)

Simple rule: If your form is falling apart, your “tired legs” are changing the load pattern.

“Okay… but my knees hurt when I run.” What should I do?

The way I explain it is: pain isn’t automatically damage, but it’s definitely information.

Here are the first tweaks I usually make with people:

• Reduce dose: shorter runs, fewer days per week

• Slow down: easy pace should feel genuinely easy

• Avoid fatigue stacking: don’t add speed + hills + distance in the same week

• Run–walk intervals: often a game changer for sensitive knees

• Strength support (2x/week): quads, glutes, calves (your shock absorbers)

Green light: mild discomfort that settles within 24 hours and doesn’t trend worse week to week.

Yellow/red light: sharp pain, swelling, locking/giving way, or pain that ramps up each session → get it checked.

If you don’t like running… walking is elite for “anti-aging”

If running isn’t your thing, walking is one of the best-supported habits for healthy aging — and the research is getting even stronger.

Walking and healthy aging: what it helps (and why)

1) Slower biological aging signals

• A Mendelian randomization study found faster walking pace may causally reduce epigenetic age acceleration(i.e., slower biological aging signals), with pace mattering more than total duration. (Chen et al., 2024)

2) Lower inflammation + better cellular “cleanup”

• Regular aerobic activity helps counter “inflammaging” and improves oxidative stress balance and cellular repair pathways (including autophagy). (McPhee et al., 2016; Vatner et al., 2020; Nilsson et al., 2019; Simioni et al., 2018; Escobar et al., 2018)

3) Independence, strength, and fall-risk protection

• Even low-intensity walking supports function and reduces risks linked to frailty and decline. (DiPietro, 2001; McPhee et al., 2016; Izquierdo et al., 2021)

• Walking-based programs improve gait speed, leg strength, balance, and daily function tests in older adults. (Jamrasi et al., 2025; Parivash et al., 2024; Bai et al., 2023; Ploydang et al., 2023; Bortone et al., 2021)

4) Brain + heart protection

• Habitual walking pace/distance is linked to lower cardiovascular risk — even in adults 75+. (Soares-Miranda et al., 2016)

• Mobility measures like walking speed also track closely with brain health markers. (Sampatakakis et al., 2023)

If you want a simple weekly starting point (choose your lane)

Option A: You want to run (knee-friendly)

• 2–3 runs/week, mostly easy

• Start with run–walk (e.g., 1 min run / 1–2 min walk x 10–20 min)

• Add 10–15% total time per week max if things are calm

Option B: You don’t want to run (still incredible)

• Brisk walking 20–30 min, 4–6 days/week

• Aim for a pace where you can talk, but you’re slightly breathy

• Bonus: add 2 strength sessions/week (even 15–20 minutes counts)

If you only remember one thing:

Consistency beats intensity. And pace matters more than people think.

Practical takeaways

• Recreational running is not generally bad for your knees, and may be protective compared with sedentary living. (Alentorn-Geli et al., 2017; Lo et al., 2017; Dhillon et al., 2023)

• The bigger risks are high BMI, prior injury/surgery, and running through fatigue. (Hartwell et al., 2023; Van Middelaar et al., 2022)

• If you don’t like running, walking is a powerhouse habit for healthspan: function, heart, brain, inflammation, and aging markers. (Chen et al., 2024; Soares-Miranda et al., 2016; McPhee et al., 2016)

Until next month — have a physically active month 💪

If you need an in-clinic appointment, I’m currently seeing patients in Notting Hill, Kensington & South Ken 📍✨

Message me to book in 📩✅

Kosta