Is A Run Streak Bad For Your Body?

Man running at sunrise
(Image credit: Ezra Bailey / Getty Images)

Welsh runner Helen Ryvar is currently 327 days into a half marathon run streak and says she has “never felt stronger or fitter”.

Meanwhile, across the pond in Miami, her running soulmate Mika Shevit has hit 717 halfs in a row with zero injuries.

British athlete and businessman Ron Hill, who died at the age of 82, ran at least a mile a day for 52 years and 39 days—a record that is yet to be surpassed.

And although these streaks are at the extreme end of running, thousands of people take up the Run Every Day (RED) challenge each January.

There are many reasons people start run streaks. It could be the enjoyment of a challenge, a desire to get fit or lose weight, to raise money for charity, or simply to create space for themselves each day to clear their head.

But is a run streak really a good idea, particularly when rest and recovery is such an integral part of training and is where adaptation occurs? Elite athletes always build rest days or weeks into their running schedule and a running coach is highly unlikely to encourage a streak.

What Are The Risks Of Run Streaks?

Research in this area is scant thanks to the difficulty of measuring streaks and the long-term impacts, but the experts we spoke to all expressed concern, while acknowledging the risk to each individual will be different depending on previous training history, lifestyle, nutrition and how they approach the streak.

Although the precise risks are unknown, a streak could potentially put strain on the musculoskeletal system as well as hormones, says accredited sport and exercise scientist Alan Ruddock.

“What’s the effect on testosterone, cortisone and other stress hormones?” says Ruddock. “It could be very stressful without knowing about it because motivation could override these things. There is a lot that is unknown.”

And the long-term impact is difficult to measure. For example, a meniscus injury 10 years after a run streak could be wear and tear, or it could be linked to the streak, says former British middle-distance runner Lewis Moses, who runs New Levels Coaching.

“The biggest risk with run streaks is that people start doing things they’re not prepared for. We want to overload the system with a training plan, but we want the adaptations to come from the rest and recovery. With run streaks it is just overload.”

And the mental pressure can often be overlooked and can lead to an unproductive feelings of failure and guilt, says Moses.

“One of the big dangers is the mental side. If people start missing days what does that do to their mindset—do they start feeling bad? All of a sudden they are in a worse place than when they started because they feel they have failed,” says Moses.

Another potential risk is burn-out, particularly if you don’t listen to your body and take a rest day when you need it.

“Things like glandular fever—the research points to a link with overtraining, and overtraining could come from a streak," says Moses. “It is worth considering whether it is more beneficial to implement long-lasting change rather than a short-term hit and run the risk of injury.”

How Can I Mitigate The Risks Of A Run Streak?

Intensity is the key. Running at an easy effort every day is far less impactful than day after day of hard runs.

"We are told to walk every day and a brisk walk is not that different from a low-intensity run, so it really comes down to intensity and impact," says Ruddock.

Moses agrees: “If you are going to overload one thing such as volume, then you have got to reduce something else like the intensity. Running at an easier intensity will help and put you at less of a risk of injury.”

Varying the distance, terrain and footwear can also help.

Ryvar gets up at 4am every day to run an easy pace half marathon, before working all day as a cleaner. She says she knows to take it slowly and add variety.

Helen Ryver wearing running clothes on a hill next to a stone monument on top of a hill

(Image credit: Helen Ryver)

“I mix up my routes daily to allow for hill days, flatter days and days where I can incorporate some Fartlek work. I take roads, trails and races. I’m conscious of mixing up my terrain and I wear good-quality trainers. I believe in listening to your body and if I need extra sleep I catch up at the weekends," she says.

Ryvar believes that having a physical job helps her stay strong and limber, and she prepared for her streak by building up her mileage before starting. 

“I’ve had no injuries whatsoever. I know to take it slow, not to rush and always run to my ability on any given day.”

Another aspect to consider carefully is nutrition because a run streak needs to be matched with increasing your daily calorie intake. Fueling appropriately will also help with recovery and avoiding energy deficit syndrome.

“It’s a fine balance between intensity, volume, energy availability and recovery,” says Ruddock.

Lily Canter

Lily Canter has worked as a journalist for more than 20 years and currently specializes in running and fitness. She regularly contributes to Coach as well as Runner’s World, Well+Good, Fit&Well and Live Science. Lily is a UK Athletics running coach, the founder of the Great Bowden Runners club and a participant in multi-day ultra races. Her biggest racing achievement to date is placing second at the Ultra Challenge 100km in the Lake District. She has a BA in English Literature, an MA in Print Journalism and a PhD in Journalism Studies. She is also co-host of the award-winning podcast Freelancing For Journalists and teaches feature writing, podcasting and freelancing to university students.