I'm a GP — here's how to know when you're running too much and how to prevent injuries

With the sport’s growing popularity comes more injuries. Dr Aisling Farrell explores ways to prevent them

Fri, 05 Sep, 2025 - 01:00

Dr Aisling Farrell

Running was her passion. It was the time of the day that was hers alone, whether she was chasing interval sprints or an easy run to clear her head. Over the years, she had competed in multiple endurance events and took pride in her consistency and fitness.

Her right knee was the only thing that ever threatened to get in her way. A niggle that gave her trouble on and off for years, usually after a spike in training intensity. It was annoying but manageable.

After having her baby, she was keen to return to racing. She signed up for a half-marathon and put together a six-week plan. Soon into her training block, however, that familiar knee pain resurfaced, unwelcome but not unexpected. Still, she kept going. It had always settled before. Then one morning, while carrying her baby down the stairs, her knee gave way. The pain was so intense that she had to stop and sit mid-step. For the first time, she couldn’t carry her baby. That moment was the wake-up call that finally brought her to our practice.

When we looked at her MRI result, it confirmed that this wasn’t a new injury. Instead, it was the accumulation of years of pushing through discomfort, skipping the necessary strength work and sidelining recovery. And now she was out of the sport that brought her so much freedom and joy.

Reality of running injuries

Unfortunately, this isn’t an isolated event. Running has grown in popularity in recent years and is a great way to improve cardiovascular health and fitness levels. (https://bjsm.bmj.com/content/54/15/89 )

However, injuries are common, affecting approximately 26% of runners. https://pubmed.ncbi.nlm.nih.gov/34478518/ ) One moment you’re chasing a personal best, the next you’re googling ‘tight IT band’ or ‘heel pain after running.’

Injury is the number one reason people stop a running programme. (https://pubmed.ncbi.nlm.nih.gov/29934211/) And while we tend to think of injuries as a sudden event, due to a wrong step, a twist or a fall, often injuries build up slowly. They can start with a tight calf or a niggle in the knee, like with my patient. These are warnings that should not be ignored.

Why do running injuries happen?

Training errors are one of the biggest culprits. Overtraining is a well-established contributor to running-related injuries. (https://pubmed.ncbi.nlm.nih.gov/36070426/) Jumping into a race without adequate preparation, increasing the mileage too quickly or returning after a break without a structured plan increases your injury risk. And if we add in poor recovery, inappropriate footwear or training imbalances, it is a recipe for injury.

Many injuries are preventable

Prevention does not mean you have to stop running. It means being smarter about how you train and recover. If you’re returning after a break, whether due to illness, a new baby or just life getting in the way, it can be tempting to jump straight into an intense training block. While a ‘six-week to marathon’ plan may sound motivating, it often doesn’t allow enough time for your body to adapt to the training load. Running is physically demanding, and to ensure longevity in this sport, building strength and mobility is equally as important as chasing running goals. It is also important to be honest about your training history, recovery and health to date.

Where should you start?

Dr Aisling Farrell: Prevention does not mean you have to stop running

Strength training: A 2018 meta-analysis demonstrated the effectiveness of strength training in reducing the risk of sports injuries. (https://bjsm.bmj.com/content/bjsports/52/24/1557.full.pdf) A structured, progressive strength programme that complements your running plan not only helps with injury prevention, but it can also improve form and performance. Many running apps, such as Runna, now also integrate strength programmes alongside the running plans.

Pace yourself: Excessive training has been associated with running-related injuries. ‘How much running is too much?’ was the subject of a recent study published in the British Journal of Sports Medicine. In this study, researchers demonstrated a significant increase in running-related injuries when the distance of a single running session exceeded 10% of the longest run in the previous month. https://bjsm.bmj.com/content/early/2025/07/07/bjsports-2024-109380 With any new running goal, aim for a progressive increase in distance over a number of weeks rather than a sudden large increase in mileage.

Take time for recovery: Lifestyle factors play a crucial role in our performance. Good quality sleep of at least seven hours per night, managing our stress levels and prioritising our nutrition, to include high protein, wholegrain carbohydrates and healthy fats, ensures that our body can recover from the physical demands of training. Compression garments, saunas, and cold plunges all have their place, but they mean little if we don’t prioritise the basics.

Smart training: If running is your passion, protecting your ability to run, now and into the future, should be a priority. Training plans should be personalised to your fitness levels, injury history and goals. They should incorporate strength work, build in recovery time and increase load gradually, ensuring you are listening to warning signs along the way.

Fit for life

My patient thankfully did not need to give up running, but did re-evaluate her approach to training. By incorporating a structured plan that focused on strength, load management, recovery and nutrition, she’s back running and looking towards her next race.

So if you are a runner who has been ignoring that niggle, jumping into races at short notice or skipping strength and recovery, consider this your invitation to pause and reassess. Train not just for your next race, but for a lifetime of running.