Whether you’re prone to injury, want to get faster or are simply looking to switch up your training routine, it might be time to consider the 1.5:1 rule – a simple training principle that content creator Imogen Cotter recently posted about on Instagram.
The former professional cyclist said that it even helped her achieve a sub-1:30 half marathon (4:13 min/km / 6:47 min/mile) with just one run a week.
While Imogen's former sporting pursuits mean she would have been working with a good existing fitness base, it's a training rule anybody can apply.
How She Ran a 1:29 Half Marathon with Just One Run a Week
‘As a former pro cyclist, I know how to push my body hard on the bike, but I have struggled to build up that same volume and mileage on the run – whenever I run more than three days in a week, my body doesn’t feel very happy about it,’ explains Imogen.
‘I sustained some pretty serious knee injuries in my racing career, and building up a training program that can allow me to progress while also taking care of this is something I feel very passionately about.’
Her approach is simple: cycle to build volume and support recovery.
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‘At the end of the day, your heart and lungs don't know if you’re on a bike or in a pair of running shoes, so why not mix it up?’
Imogen kept one key session of running a week in her plan, which consisted of long blocks at her goal marathon pace of 4:15/km.
What Is the 1.5:1 Rule?
That’s where the simple but effective 1.5:1 rule comes in.
‘When I convert a running workout to a cycling workout, I multiply the timing by 1.5. For example, if I have a 60-minute run to do, I’ll convert it to a 90 minute cycle,’ Imogen explains.
‘Running places a higher energy and muscular demand on the body because you’re absorbing impact on every stride; cycling is lower impact, so if I am trying to convert a workout to achieve a similar aerobic stimulus, I use the 1.5:1 rule.’
It’s a cross-training principle that Imogen wishes she’d followed earlier on in life.
‘I first started to take running a bit more seriously at about 17; I had always been sporty, but that was when I decided to focus on running – I wish I could go back in time and tell younger me about how helpful cross-training could be as a part of my programne,’ reflects Imogen.
‘I was constantly injured and under-fuelling as a teen runner. I would go through the same old cycle continuously: train hard, get a great training block in, get injured, cross-train, start from scratch,’ she adds.
‘If I had understood that cross-training wasn’t only useful during rehab from injury but as an integral part of my training routine, I could have saved myself a lot of heartache.’
Hannah Bradfield is a Senior Health and Fitness Writer for Women’s Health UK. An NCTJ-accredited journalist, Hannah graduated from Loughborough University with a BA in English and Sport Science and an MA in Media and Cultural Analysis. She has been covering sports, health and fitness for the last five years and has created content for outlets including BBC Sport, BBC Sounds, Runner’s World and Stylist. She especially enjoys interviewing those working within the community to improve access to sport, exercise and wellness. Hannah is a 2024 John Schofield Trust Fellow and was also named a 2022 Rising Star in Journalism by The Printing Charity. A keen runner, Hannah was firmly a sprinter growing up (also dabbling in long jump) but has since transitioned to longer-distance running. While 10K is her favoured race distance, she loves running or volunteering at parkrun every Saturday, followed, of course, by pastries. She’s always looking for fun new runs and races to do and brunch spots to try.
