Running is one of the most popular ways to stay active across Chandlers Ford, Eastleigh and Hampshire – from local parkruns, great 10Ks like the Eastleigh 10k and Marwell 10k, fantastic running groups, such as Eastleigh Running Club, Chandlers Ford Swifts and the Chandlers Ford Running Community and the ABP marathons. But a question we hear frequently at goPhysio is:
“How do I know if I’m doing too much running?”
A major study published in the British Journal of Sports Medicine (2025) provides a clear, evidence-based answer – and it challenges some common assumptions about training and injury risk. This was their most read article of 2025!
What Did the Research Study Look At?
Researchers followed 5,205 adult runners from 87 countries over an 18-month period, using GPS data from wearable devices to track running distance and training patterns. Instead of focusing only on weekly mileage, the study looked closely at individual running sessions to identify which types of runs were most strongly linked to injury.
The Key Finding (In Simple Terms)
👉 Injury risk increases significantly when a runner completes a single run that is more than about 10% longer than their longest run in the previous month. In other words:
- It’s not just about how much you run overall
- It’s about sudden spikes in distance during one session
What Does This Mean in Everyday Language?
Here’s a straightforward example:
- If your longest run in the past 4 weeks has been 10 km
- Then you’re suddenly running 11 km or more in one session
- This is a red flag for injury risk
Even though an extra kilometre may feel manageable, your body – particularly your tendons, bones and joints – may not yet be adapted to that increase.
Why does this matter?
Your fitness improves faster than your tissues.
Your heart and lungs may feel fine, but connective tissues adapt more slowly and are more vulnerable to sudden load increases.
Why Weekly Mileage Isn’t the Whole Story
Many runners believe that as long as weekly mileage increases slowly, they’re training safely. This study shows that:
One “stretch too far” run can be more important than total weekly volume.
This helps explain why injuries often occur:
- when runners suddenly increase their long run
- after illness, holidays or busy work periods
- when returning from injury too quickly
- during race training without adequate progression
What This Means for Runners in Hampshire
Whether you’re:
- starting Couch to 5k
- building up to start taking part in your local parkrun
- preparing for a 10K or half marathon
- or returning to running after injury
this research highlights the importance of gradual, controlled progression, especially with your longest run.
Practical, Evidence-Based Tips for Safer Running
- Track your longest run, not just weekly mileage
- Increase long runs slowly and deliberately
- Be cautious after time off or disrupted training
- Combine running with strength training and recovery
- Listen to early warning signs such as persistent soreness or niggles
How Physiotherapy Can Help Reduce Running Injuries
At goPhysio in Chandlers Ford, we regularly support runners whose injuries began after subtle increases in load – not because they were doing “too much”, but because their bodies weren’t ready yet. Our team help by:
- reviewing training load and progression
- identifying strength or mobility gaps
- creating return-to-run plans after injury
- supporting long-term, sustainable running performance
The Bottom Line
✔️ It’s usually not about running too much
✔️ It’s about running too much, too suddenly
✔️ Your longest run matters more than you think
✔️ Small, steady progress helps keep you running injury-free
If you’re dealing with a running injury, managing a niggle, or planning your next event, an evidence-based physiotherapy approach can make all the difference.
Need support with running injuries or training progression?
📍 Visit goPhysio in Chandlers Ford – supporting runners across Eastleigh, Winchester and Hampshire to stay active, strong and injury-free.
Frequently Asked Questions: Running Distance, Load & Injury Risk
How much running is too much? Running becomes a higher injury risk when you suddenly increase the distance of a single run by more than about 10% compared to your longest run in the previous month. It’s not just total mileage – sudden spikes matter most.
Is it okay to increase my running distance every week? Yes, as long as increases are gradual. Your longest run should progress slowly, especially if you’re building towards a race. Sudden jumps, even if they feel manageable, increase injury risk.
Does this apply to beginners as well as experienced runners? Yes. The research included runners of all levels. In fact, beginners and returning runners may be at even greater risk, as their tissues are less adapted to load changes.
Is weekly mileage less important than long runs? Both matter, but this research shows that one overly long session can be more harmful than a steady weekly increase. That’s why many injuries occur after a single “big” run.
Why do I feel fit but still get injured when I increase distance? Your cardio fitness improves faster than your tendons, bones and joints. You may feel capable, but your tissues may not yet be ready for the increased load.
Does the ‘10% rule’ still apply? This study suggests that even the commonly used 10% rule may be too aggressive for some runners, particularly when applied to the longest run. Smaller increases may be safer, especially after time off.
What injuries are most linked to sudden distance increases? Sudden spikes in running distance are commonly linked to:
- Achilles tendinopathy
- Shin splints (medial tibial stress syndrome)
- Knee pain (including runner’s knee)
- Hip and pelvic overload injuries
- Stress reactions or fractures
What should I do if I’ve already increased my distance too quickly? Reduce load slightly, prioritise recovery, and address any early pain signals. Ignoring niggles often leads to longer time off later. A physiotherapist can help adjust training safely.
How can physiotherapy help runners avoid injury? At goPhysio in Chandlers Ford, physiotherapy for runners may include:
- reviewing training load and progression
- identifying strength or mobility deficits
- gait and movement assessment
- return-to-run planning after injury
- long-term injury prevention strategies
When should I see a physio about running pain? If pain:
- lasts more than a few runs
- worsens as you run
- affects your stride
- returns every time you increase distance
- it’s a good idea to seek advice early.
Do you help runners locally in Eastleigh and Hampshire? Yes. goPhysio supports runners across Chandlers Ford, Eastleigh, Winchester and Hampshire, from parkrun beginners to competitive athletes.
