Can too much cycling negatively impact running?

I have been doing lots of cycling in the past 6 week, while I have not been running too much due to niggling injury.

Now I am running a bit more, my running performance seems to be reduced. I have also noticed that my Quads have increased in size significantly, I guess due to the increase in cycling power.

Question: is my running slow because I have not been running much? or is my running slow because my leg muscles have changed due to cycling?

I am still not 100% running fit, I can feel general tighness, so I am not pushing either pace or distance

I doubt it’s a totally linear question to be honest Matt. Your increased aerobic and lactate clearing systems etc will clearly be enhanced from your cycling, and this will have a positive effect.

The lack of running will have caused a drop off, and cycling just doesn’t replicate those exact muscles in the same way. I guess if you’ve really had a significant change in muscle mass, then that’s going to potentially effect your gait as well as being more weight to carry when running. A few weeks of running would likely settle things down I’d imagine. If you cycled for a year with limited running, as opposed to 6 weeks, I guess things would be a bit different.

I’ve no experience in this of course, just my thoughts. But I think things will settle over time, especially as a return to running will likely cause a reduced cycling volume.

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I noticed a different gait while running, but that may be down to injury recovery. Its surprising how much muscle has increased. My shorts are all loose around the waist and tight round my thighs

At the top end, specificity is clearly pretty important. So a lack of running will mean your run isn’t quite there/as sharp.

But I have always found at least some transferral between bike to run. And the run comes back quickly. With absolutely zero equivalence the other way.

What’s the saying? Bike for show, run for dough?

There is a Lboro paper about the lack of transferability of cycling to run training…i will try and find it some day (in a box of many similar papers).

There will potentially be some benefit, but that would probably be more than offset by the lack of running.

no, but i get what you are trying to say…

I’ve always found that running translates to cycling easier than cycling translates to running when looking at a ‘lopsided’ equation.

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Sounds like you’re going to be the quintessential MAMIL next season Matt; just throw in zero swimming :wink: :joy:

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I might just become one of those permanent Zwifters


Yes, that’s where races and KQ slots are won & lost.

Did a lunchtime run in my Vapor Fly’s, what a difference to the Pegasus 36: hardly noticed any soreness from injury. Good tip for anyone recovering from injury, the Vapor Fly’s are magic

Despite no injury problems, and running at a relatively sedate 5m/km, quads hurt, hamstrings hurt, right calf hurts… not like injury hurting, more like “what is this abuse” sort of pain. Maybe this has something to do with smashing my legs on the bike this weekend.

On the positive side, my HR avg was 138bpm, with 80% below 140, so an easy Z2 run. The engine is still there, the muscles just need a bit of tuning


I’ve always had issues with the running when I up the cycling during summer, I think some of it might be a loading issue TBH, it’s difficult striking the right balance and not overtraining, particularly in recent years.

I’ve found that I can carry forward spring marathon running for a month or two assuming I don’t come out injured by one decent run session P\W, or parkrun and a longer run.

I can hold some performance for 70.3’s, but IM’s are a bit different, I’ve got a couple nearly right, but I think that is as much a fuelling\pacing issue.

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Weird. Shows we’re all different. I can run pretty well off cycling only. I have absolutely no bike power, or endurance, off a run only programme.

Don’t think there’s any answer to this that’ll be consistent for everyone. I’m currently not running at the minute due to a niggle. 6 days a week on the bike/turbo now, 11-14 hours. Plus strength and conditioning and stretching. My highest heart rate training is when running. I can’t quite hit the highest heart rates on the bike. So my faster running suffers more when I’m not on on the bike. I can usually maintain fitness quite well but the running muscles get deconditioned and they take a while to build back up again so I have the fitness to run pretty much as I did before I take time off running, but I have to be careful because of muscle soreness. I was injured in the lead in to 70.3 SA worlds in 2018. My run was a miracle. But I literally couldn’t move the next day. I couldn’t get out of bed. Legs were absolutely ruined. Took a while to come round again… at the minute I’m telling myself that a few weeks off running doesn’t really matter and I am quite enjoying seeing my biking improve.


How much stretching and mobility work do you do? Cycling can lead to tight quads and hip flexors which will impact your running form

Not enough stretching and mobility work

I did some foam rolling of the quads for the first time in a long time yesterday. I usually just get massage (as I’m lazy). All I can say is ouch.

I have to mobility work 4-5 times per week and have done for the last 5-6 yrs. Without it, I literally can’t walk properly. But that’s genuine mobility, rather than strength.

At the gym at my old work, I used to some strength/weights a couple of times per week, which seemed to help with running.

But I swear, after every dedicated foam rolling sessions, I end up with tight calves for a few days and have tp tread carefully. (and weird dreams of course :grin:). Either I’m rolling incorrectly, or it isn’t beneficial.

At the gym, I used one of those softish orange rollers. At home I have a Covacure which is much harder but I get the same result.

I’ve started using a massage gun:

Too early to pass judgement…!

My physio recommended these the last time i saw her, she used it on me, and it seemed quite effective. I got too scared to buy one though as i a) i’m not spending £200 on the one that she recommended and b) there then seems to be about 20 identical looking ones on anything from amazon to ebay that range from £30-£200. But they look literally identical … so i guess a bunch of factories in China have managed to get hold of the designs and are just pumping them out with different labels. I wonder if it’s hit or miss if you get one that’s as powerful as one of those travel fans you get in a 99p shop or one that’s like a pneumatic drill. Similarly will the battery last 3 days before it explodes, or 3 years?