Running: why intense or excessive running isn’t always good for you

Posted by for Workouts

Fitness writer Miranda Larbi shares why running intensely all the time can actually backfire. 

Running can be addictive – ask anyone who’s been doing it for a while. Despite it being frustrating, painful, or boring at times – we come back to running all the same. Pounding the pavement can make us feel alive, strong, and healthy. When something has the ability to boost our feel-good hormones, it’s no wonder that so many of us take it too far.

I’ve trained for three marathons and one ultramarathon, so clocking up mileage is something that I’m relatively used to. Even so, at times I’ve still found myself struggling with double vision, intense sweating or an alarming urge to purge mid-commute run. During lockdown, I even attempted to continue running despite two sprained ankles. I admit, runners like myself are prone to overdoing it – no matter how experienced we are.

Thanks to gyms being shut over lockdown, many of us have been running more than ever. Sports Direct reported a 218% increase in running trainers sales over spring and a 243% increase in running activewear, compared to the same period last year. It seems as if the pandemic has led to even the most reluctant runner lacing up their trainers and heading for the trails. Predictably, this sudden interest in running has also led to millions of people becoming injured. Bupa has reported that this ‘newfound enthusiasm’ has caused 7 million injuries – from sprains to back injuries – with men being twice as likely as women to become injured. 

So, what happens to our bodies when we’re pushing too hard or for too long?

Running can improve heart health, boost our mood and help us to build muscle – but overdoing it can undo those same benefits. One reason for this is stress. We need to produce the stress hormone cortisol just to get out of bed in the morning, but we don’t want to produce too much as our body can’t distinguish between different types of chronic stress. This means that we physically react in a similar way to exercise and work stress as we would to more significant dangers. When that stress is prolonged, our body goes into survival mode - the same kind of instinct that kept our ancestors agile and ready to avoid attacks from dangers like hairy mammoths many years ago. Running hard for long distances puts massive stress on our body, so we might find our menstrual cycles becoming disrupted, sleep patterns going haywire, and our appetite decreasing as a result.

“When we talk about overtraining, we are talking about the management of stress in the body - specifically, the stress we are imposing on our bones, tendons and ligaments, and muscle,” explains Chris Baird, head of training at Oro and strength and conditioning coach at Loughborough University’s Sports Performance Team. ”In optimal circumstances, when we train well, that ‘stress’ creates what we call an adaptation leading to progress or improved performance over time.” Too much of that stress and we start to see tissue deteriorate, and ligaments and tendons weaken.

running-build-muscle
Running: Excessive intense running can lead to muscle and bone injuries, including lowered immune response

Dr Grant Trewartha is head of biomechanics at running company NURVV. He explains that while “the human body can adapt very well to longer distance running” with enough time and rest between heavy sessions, “excessive ‘overreaching’ leads to various negative consequences such as muscle and bone injuries, lowered immune response (not ideal when we’re dealing with a pandemic), and psychological issues.” That “overreaching” tends to happen when you increase the amount or intensity of your running, and too quickly.

Despite how good cardio can be for our hearts, excessive running may actually have the opposite effect. A 2011 study published in the journal Nephology looked at the cardio impact running had on marathon runners after finishing long distance events. It found biomarkers associated with heart damage present in athletes’ blood. While those damage indicators usually go away by themselves, regularly pushing your body to its limits means that temporary damage can become more permanent - leading to physical changes of the heart, such as scarring and thicker walls. That then heightens the risk of sudden cardiac arrest, heart rhythm issues and disease - especially in those with underlying heart disease. Very often, runners don’t know they’re at heightened risk until it’s too late. Which may be one reason we often read about seemingly healthy athletes passing away during or just after marathon events.

Overdoing it isn’t just a physical issue, it can cause psychological problems too. Performance psychologist Chloe Oldfield says that “running at too high of an intensity and frequency leaves us exposed to the risks of overtraining or burnout. Psychologically speaking, this can involve lower moods than usual – including feelings of apathy, fatigue and loss of confidence due to potential performance decrements.”

Signs you’re running too much

It’s normal to feel tired and achy when you’re completing a training program, but there’s a difference between post-run DOMs and full-body fatigue. Symptoms of vary from person to person, but according to Dr Trewartha, there are “well over 100 signs and symptoms” associated with overtraining. Common signs include fatigue, nagging injuries that won’t go away, sleep issues, irritability and depression. 

Runners who are covering excessive miles also need to be wary of RED-S (Relative Energy Deficiency in Sport). RED-S occurs when there’s an imbalance between energy expenditure and intake, which can lead to various physical and psychological imbalances – and it’s something that particularly affects women. The British Medical Journal has published a statement from the International Olympic Committee (IOC) looking into the “Female Athlete Triad”, or RED-S. It linked menstrual function, bone health and energy deficiency together in a triangle, while acknowledging that over-exercising can also lead to cardiovascular, gastrointestinal, immunological, concentration and coordination issues.

If you’re running despite being injured, it’s time to reevaluate your training. No runner needs to push through a rolled ankle or pulled muscle, and if you are committed to training with an injury, you may have fallen down the addiction rabbit hole. Chloe warns us to watch out for potential signs of obsessive running. “Some may include training persistently through injury and fatigue, feeling as if one’s self-worth is based on running, consistently sacrificing relationships and other activities for running, and feeling anxious if running is not possible.”

Two in one gym shorts
Running: avoid intense running if you're injured or already feel fatigued

How to prevent excessive running

First off, it’s important to point out that our bodies are all different. Some of us might comfortably run 40 miles per week, while others prefer to cap their runs at 20 miles. The key is to build up weekly mileage gradually, while using a structured plan. That’s where fitness trackers can come in handy. 

Garmin trackers, for example, come with running training plans, as well as biomarkers to determine your sleeping patterns, stress levels, heart rate and nutrition levels (which is useful to know if you’re at risk of burning more calories than you’re consuming). Tracking your runs is an easy way to make sure that you’re not going over a set weekly mileage and can help you to slowly increase the load when your body is able to handle it. Of course, you can’t rely on tech and data entirely; how your body feels is as important as what your watch and phone tells you. If your ankles are telling you to rest, don’t be tempted to go for a run just because your watch keeps telling you to move.

Most newbie training plans for 10K runners will build up to a maximum of 20 miles per week, with at least three days of rest. First time marathoners can expect to run around 40 or 50 miles per week from runs of different lengths and paces; with rest days being non-negotiable. Fundamentally, knowing your goal is crucial. There’s no point in trying to increase distance or intensity too quickly, especially if it bears no relation to your ultimate goal. Someone looking to run a sub-60 minute 10K doesn’t need to be clocking up 20-mile long runs every Sunday.

To remain agile, motivated and injury-free, Baird recommends leaving at least six hours between training or running bouts, while changing up the type of training you do. 

“Always make sure there is plenty of recovery built into your training schedule via rest days, lighter jogs or cross-training with other forms of exercise,” Dr Trewartha advises. “Some runners have excellent training habits, but there is still a tendency to neglect other forms of exercise that contribute to physically preparing your body for running – including strength training, yoga and flexibility training.” Running drills like skipping, hopping and hill sprints also help to improve technique, performance and energy expenditure. 

Lastly, he says, we can’t forget about non-running lifestyle factors. Nutrition and sleep are hugely important to how well we perform, so it’s vital that we make them solid parts of our training regimen.

So, by all means run. Run free, run strong and run happy – but recognise when to run and when to rest. 

Follow @StrongWomenUK on Instagram for the latest workouts, delicious recipes and motivation from your favourite fitness experts.

IMAGE: Getty 

Sign up for workouts, nutritious recipes and expert tips. You'll also get your Beginner's Guide To Strength Training.

By entering my email I agree to Stylist’s Privacy Policy

Share this article

Miranda Larbi

Miranda Larbi is a freelance fitness and wellness journalist, and qualified personal trainer. When she’s not finding new vegan places to eat, she can be found training for the next marathon or cycling across London on an old Dutchie.

Recommended by Miranda Larbi