Marathon training on a bicycle

Posted on August 10, 2025•By John Kraijenbrink•Column

I’m out for my long run. There is just one little thing: I’m doing it on my bicycle. Running for a couple of hours is not an option yet. My right ankle is still not recovered after I tore my ankle ligaments in mid-May. Yet, I have hope. Hope to be fit in time for the Antwerp Marathon. And the only way to do that, is on the bike.

Top trail and ultra runners like Katharina Hartmuth, Kilian Jornet, Toni McCann, and Jonathan Albon often train on a bicycle. Less impact, still building endurance. Okay, they are not training for a marathon, but if it works for a fast 50k, 100k, or hundred miles, why wouldn’t it work for a marathon?

Building strength

Heavy gears build strength. Riding uphill builds strength. Long rides build endurance. I know, it’s not quite the same as running, but it comes close. The legs have to work. Work hard. I can only benefit from that.

Plus, my ankle is happier riding a bicycle. Happier, not happy. It still swells up after a long ride. Just not as much as it does after a 10 kilometre run. Besides, my ankle doesn’t allow me to run two days in a row. I tried; it’s no fun. But I can run and bike the day after. Followed by another day of running. So, riding my gravel bike is a necessary evil if I want to make it to the marathon.

Injured

And I would love to run it. It’s August. This is the month of the UTMB CCC. I should have been on that starting line three weeks from now. I won’t. Injured. I was going to do my first Olympic distance triathlon. I couldn’t. Injured. Two weeks ago, I had a training camp in Garmisch-Partenkirchen. I was supposed to run up the Zugspitze. It didn’t happen. Injured. I don’t want to miss another race.

The problem is, the ankle still doesn’t look fine. My osteopath and physiotherapist think I’ve damaged more than my ligaments. He’s afraid I’ve damaged my cartilage as well. That would explain why my ankle is still swollen and still feels sore when I run.

Runner’s high

It also means I still have to take it easy. That’s the hardest thing to do. I’m missing my runner’s high. I feel better when I run first thing in the morning. Without running, I feel sluggish and can’t get anything done. I sit at my desk and stare at my screen. Or surf the internet, hoping to find something that gives me a kick. That makes me feel happy. Running is my dope. It makes my happy hormones flow.

That is also the main reason for the conflict that’s playing in my head all day. One side of me wants to push. Run, bike. The other side of me wants to take it easy. Be wise. Choose health first. Yes, running makes me happy now, but I shouldn’t sacrifice now for forever. So first heal, then run.

Balance

For now, I’m trying to find a balance. I do my speed work and long sessions on the bike; I run my easy runs and tempo intervals. It’s an experiment. And experiments are always fun. They make my happy hormones flow as well. And you? Are you experimenting, running, or resting?

Keep on running.

John Kraijenbrink

Running Coach - Massage Therapist - Yoga Teacher - Journalist - Gear Tester. I run for the joy of running. Yet, I like to challenge myself to be the best version I can be. For me that means dedicating myself to a structured training plan. You can find me on the road, trails, on my gravel bike or in the swimming pool.