Running Injuries: How to Tell “Normal” Pain from a Red Flag (And Actually Stay on Your Feet)

It’s 5:47am. The alarm goes off. It’s raining – obviously it’s raining, this is Britain. You haul yourself out of bed, lace up your trainers, and somewhere between the front door and the end of the road, your knee starts doing a Thing. Not a dramatic Thing. Just… a Thing. A twinge. A whisper of discomfort that could mean absolutely nothing, or could mean six weeks on the sofa watching other people’s Strava uploads with increasing despair.

Running injuries are, without question, the most frustrating part of this sport. And the maddening truth is that distinguishing between “my body is adapting to training load” soreness and “mate, you should probably stop” pain is genuinely hard. I’ve been getting it wrong for years. Sometimes I’ve pushed through and been fine. Other times I’ve pushed through and spent a fortune on a physio who looked at me with the quiet pity usually reserved for someone who’s eaten a Greggs on race morning.

So let’s talk about the most common running injuries, what the NHS actually says about them, and – crucially – how to reduce your chances of collecting them like a very unwanted set of Panini stickers.

The Most Common Running Injuries (Yes, You’ve Probably Had One)

According to NHS guidance on running injuries, the majority of runners will experience at least one injury per year. One. Per. Year. That’s basically a subscription service nobody asked for.

Here are the biggest offenders:

• Runner’s Knee (Patellofemoral Pain Syndrome) – That dull ache around or behind your kneecap that shows up uninvited around mile 8 of your Sunday Long Run. Usually caused by overuse, weak glutes, or running too much too soon.
• IT Band Syndrome – Sharp, nagging pain on the outside of your knee. If you’ve trained for a marathon and not experienced this at least once, are you even a real runner?
• Shin Splints (Medial Tibial Stress Syndrome) – That lovely burning sensation along your shinbone. A classic beginner trap, but experienced runners bump their mileage too fast and get it too.
• Plantar Fasciitis – The stabbing pain in your heel, worst first thing in the morning when you shuffle to the kettle like a zombie. Particularly charming when you’ve got a Parkrun PB attempt planned for Saturday.
• Achilles Tendinopathy – Stiffness and pain at the back of the heel, often grumpy in the morning and after sitting still. The NHS recommends a specific eccentric heel drop exercise protocol for this one, and it actually works.
• Stress Fractures – This is where we exit self-diagnosis territory and call the GP. Localised, pinpoint bone pain that gets worse with activity and doesn’t ease off with rest is a red flag.

Soreness vs. Injury: The Question That Keeps Every Runner Up at Night

Here’s the honest answer: there isn’t a clean, foolproof way to tell the difference. I know. Not helpful. But let me give you the framework I use, imperfect as it is.

Signs It’s Probably Just Normal Training Soreness

• It’s a generalised, dull ache across a muscle group (not a sharp, localised point)
• It eases off once you’re warmed up and moving
• It arrived 24-48 hours after a hard session or a long run
• It’s symmetrical – both legs feel similarly battered
• It improves across the week as you recover

Signs You Should Actually Pay Attention

• Sharp, pinpoint pain in one specific spot
• Pain that gets worse as you run, not better
• Swelling, heat, or visible bruising around a joint
• Pain that significantly alters your running gait
• Anything that keeps you awake at night – that’s your body shouting, not whispering
• The same issue keeps returning every few weeks

The NHS guidance is pretty clear: if you have pain that doesn’t improve with rest after a couple of weeks, see your GP or a physiotherapist. Don’t just tape it and hope. I’ve tried hoping. It has a roughly 40% success rate in my experience, and that’s being generous.

Running Injury Prevention: The Boring Stuff That Actually Works

Look, nobody wants to spend 20 minutes doing hip strengthening exercises before a Tuesday evening track session. It feels deeply uncool. But the runners who do the boring stuff consistently are the ones who actually make it to the start line. Runner’s World consistently highlights that most running injuries are overuse injuries – meaning they’re largely preventable with a bit of patience and planning.

• The 10% rule: Don’t increase your weekly mileage by more than 10% per week. It’s not exciting. It works. Most of us ignore it until we’re icing a knee on the sofa.
• Strength training: Glutes, hips, and calves. Weak glutes are behind an alarming number of common running injuries. Two sessions a week of targeted strength work will do more for your running than an extra easy run.
• Sort your trainers: Worn-out shoes are a silent injury factory. Most running trainers have a lifespan of around 300-500 miles. If you’re tracking your mileage on Strava, it’ll tell you. If you’re not tracking shoe mileage, start now.
• Vary your surfaces: Running exclusively on tarmac hammers your joints. Mix in trail, grass, or towpath running to reduce impact load.
• Don’t skip your easy runs: If every run is hard, your body never recovers. Those Zone 2 easy runs you’ve been skipping because they feel “too slow”? They’re doing more injury prevention work than you realise.
• Sleep: Boring. Transformative. Non-negotiable. The NHS recommends 7-9 hours for adults, and training load makes that even more important.
• Listen to the early warning signs: A minor niggle ignored for three weeks becomes a six-week injury. Address things early, even if it just means two days off.

When to See a Physio (Sooner Than You Think)

The British running community has a slightly masochistic attitude to injury – we tend to run through things until we physically cannot, then panic. The smarter approach is to see a physio early, when an issue is still minor. Many NHS trusts now offer direct access physiotherapy, meaning you can self-refer without needing a GP appointment first. Check your local trust’s website for details.

Private physio typically runs between £50-£80 per session in the UK, which is painful in a different way. But one or two sessions early can prevent a month of lost training. Do the maths. Then wince at both sets of numbers and book anyway.

If you’re building back from injury and trying to stay confident about your training, our piece on regaining marathon training confidence is worth a read – injury layoffs mess with your head as much as your legs.

And when you’re back running, recovery between sessions becomes even more important. We’ve covered foam rolling and recovery strategies in detail in our running recovery tips guide – it’s the unglamorous side of training that most of us underinvest in.

Real Talk

Here’s where I land after years of getting this wrong: running injuries are not a sign of weakness, bad luck, or the universe punishing you for that fifth biscuit. They are, for the most part, a predictable consequence of doing too much, too soon, with too little recovery. The frustrating part is that the line between “pushing yourself productively” and “overdoing it” moves constantly depending on your age, sleep, stress levels, and about forty other variables.

The NHS advice is solid and unsexy: rest when something hurts, build mileage gradually, strengthen the supporting muscles, and see a professional when something doesn’t clear up on its own. It’s not a magic formula. But it’s a better plan than taping your knee and hoping for the best at Parkrun on Saturday.

The honest truth? I haven’t fully cracked it either. But I’ve got fewer black toenails this year than last, which feels like progress.

If you’re just getting started and want to build a base that reduces your injury risk from the beginning, our beginner’s guide to running in the UK covers everything from first steps to your first 5K without breaking yourself in the process. Go have a read – your future, uninjured self will thank you.