What’s everyone’s thoughts on comparability of effort/fitness between running and cycling?

I’ve always thought of it as 4:1 cycling/running. Rough comparable efforts being a 100-120 miler on the bike with a marathon (eg big efforts that would be recognised as big, and ironman triathlon)

Thought experiment – wife does a 10k run in just under an hour. Is my comparable cycling effort riding 40k? Riding for an hour wouldn’t get me to that distance (at my normal speed), and doesn’t feel comparable.

I don’t run much, could do a 5k but my legs would be in bits for days afterwards. Different fitness types, just interested in seeing if there’s anything anyone uses as a guide

Lots of variables I know!

Not just fitness. Running is much harder on the body.

It varies massively, depending on who you are. They don’t cross over well.

I know marathon runners who are crap on bikes – for them, a 30 mile hilly ride is like a 20 mile run. I on the other hand am a reasonable cyclist but an absolutely terrible runner. I hurt much more after a 5 mile run than a 50 mile ride. My mate who is good at both probably considers the effort ratio 2:1 cycling to running in terms of time not distance.

I could do 100 miles on the road in about 6 hours depending on terrain, but I couldn’t even complete a marathon or even a half marathon.

Cycling time and distance are very poor indicators of effort. If you’re riding on flat terrain, you can just cruise along with very little effort. Running is always quite effortful. I would rate running as more like riding uphill – you can adjust the effort somewhat, but it’s never going to be effortless.

Too many variables to consider, principally running hurts my legs more than cycling does due to impact.

I’ve run one marathon. My legs were in bits for days afterwards. I could set off to do a 160km ride now, be back for dinner and repeat that all week. I’ve done 300km rides and felt nothing more than “a bit weary” afterwards.

Too many variables to consider, principally running hurts my legs more than cycling does due to impact.

It’s easy to overlook the impact thing in my opinion. I can’t walk much further than 1km unassisted but can do a hilly 50k mtb ride ok. Pretty sure that’s largely down to the impact of walking and running is worse for that…

The main difference is you can’t freewheel when running.

Yeah, I do regular 10km runs and there’s a massive difference when running on tarmac vs gravel or grass. During lockdown I was running on the local golf course and that was glorious. Felt like I was floating.

Main difference is that cycling is great fun.

Fixie or freehub? 😉

I don’t think there is a neat overall comparability to be honest. Have a read:

https://www.trainingpeaks.com/blog/the-differences-between-running-and-cycling-power/

Anecdotally/aside – I can’t run far (literally less than a mile) because of joint injury/foot problems that can’t bear weight and shock – but I took the middle-route (buying a foot-bike) between running and cycling.

Though I can say for sure that the sustained effort on foot-bike vs cycling feels …incomparable! Especially uphill my lungs burn in a way that they don’t whilst cycling.

Compared to calories burned (on the chart) it feels like maybe a 1/3rd tougher (aerobic/cardio) but I also work more muscle-groups and harder on the foot-bike than regular cycling. But even I find it easier to run uphill than to footbike uphill, whereas cycling uphill (with gears) is somewhere between.

I imagine it would be a similar experience for running vs cycling*

*For running couldn’t you find some similar calculation for calories burned per hour ie:

According to broad calculations from the American College of Sports Medicine, someone weighing 150 pounds who runs at a brisk seven minutes per mile will incinerate about 1,000 calories per hour. That same person pedaling at a steady 16 to 19 miles per hour will burn about 850 calories

I’ve read it claimed that running burns a fixed amount of calories (ie average 110 calories per mile) while cycling is variable?

…if you ride at 15 mph, you burn 31 calories per mile. This means if you ride 20 miles you burn 20 x 31 = 620 calories. Take the 620 calories and divide by 110 calories per mile for running and you get 5.63 miles of running to burn the same number of calories. Therefore, riding a bicycle 20 miles at an average 15 miles per hour is equal to running 5.6 miles at any speed.

http://davesbikeblog.squarespace.com/blog/2007/9/24/running-vs-cycling-burning-calories.html

For me, it feels like I have to spend roughly double the time cycling to get the same kind of workout.

But as above, it’s a different kind of workout anyway.

I can ride all day, but my knees don’t like running more than about 15k.

Running is always quite effortful. I would rate running as more like riding uphill – you can adjust the effort somewhat, but it’s never going to be effortless.

Bad technique….if you are doing any distance it should be near effortless as much of the time as possible.

Main difference for me is/was running you can mostly completely switch off, even on gnarly runs (I used to do a lot of fell and horseshoe’s) in a way you can’t on a bike.

It’s easy to overlook the impact thing in my opinion. I can’t walk much further than 1km unassisted but can do a hilly 50k mtb ride ok. Pretty sure that’s largely down to the impact of walking and running is worse for that…

Can be worse… walking completely screws me up (back)…. especially 1 hour round town. I’m better off running… which is less than great on by buggered knee and ankle but not bad for me.
Cycling as you say….

Bad technique….if you are doing any distance it should be near effortless as much of the time as possible.

Technique helps, but some people just aren’t built for it and it’ll never be effortless. Same as some people aren’t built for sprinting.

Can be worse… walking completely screws me up (back)…. especially 1 hour round town. I’m better off running… which is less than great on by buggered knee and ankl

I used to do multi-day walks but stopped being able to due to foot pain.(that’s the main reason I took up cycling). A long days walking will still result in sore feet. It’s mostly going downhill that causes the problem. I can run downhill without the same issue.

Molgrips

Technique helps, but some people just aren’t built for it and it’ll never be effortless. Same as some people aren’t built for sprinting.

Fair comment … but the vast majority I used to see* that struggled could improve things immensely with technique.
Myself and my best mate used to run everywhere and do lots of ultras and fell running but we’d also lead short 10k or so runs for kick boxing warm ups. Lots of fit people you could just see made it “difficult” and improved enormously with tips and practice. Sure they might not be winning races but they started to find it more pleasureable… and put in much less effort.

[bear in mind these were pretty fit and the run was a warm up activity rather than meant as exercise in itself but a few were absolutely knackered to start with and improved way beyond “different muscles” etc. and they were visibly running much better]

I think it depends greatly on effort. A 10k run will take me 45mins and I will be knackered immediately after it, but fine in an hour or so. Similarly, I can go out and do an hours ride aiming for 36-38kph average and be in an equal state. But, say I reduce my effort by about 20% the run will still have a similar feeling, the ride will not. That’s because when you’re not pushing on a ride, you can freewheel, but on a run, you have to keep running.

A 3.5-4hour marathon is far more devastating to your body than a 3.5k 100k ride even at 32+Kph. At endurance pace for both running and cycling, double the time is required to have the same physical feeling.

I state all of the above having done and continuing to do the things listed.

P.S. Marathons are dumb – they bloody hurt. Why do I keep doing them?

Marathons are dumb – they bloody hurt. Why do I keep doing them?

I hear you. Worse, I do then and 3 days later enter an ultra. I am an idiot.

To answer the OP, I reckon a marathon is roughly an imperial century.
But, and it’s a big but.
There are many who can do one and not the other, it’ll depend on the individual.
When I started running I could ride 100 miles with no prep but couldn’t run to the end of my road.
Now I can run easily, I’ve just come back from a gentle 16 miler and feel fine, but did a 70 mile bike ride a week or 2 ago and it knocked me about a bit.
Part of the reason I like running is that it’s time efficient, I can go and do a fast 5k and feel shatters, 20 mins in a bike is barely a warm-up. I find is also better for the mind, as another poster mentioned, I truly empty my mind in a run, particularly a trail run, I don’t get that on the bike either on or off road.

Not disagreeing that technique is important (indeed I’ve said this many times on here and been derided for it) but for a lot of people it’s never going to be ‘effortless’..!

I’ve only done trail maras, but 30km+ of hill running takes me to dark places I’ve rarely managed on a bike. Thing is, when you’re relatively new to the sport like I am, running downhill or flat is not resting. You’re still hobbling along with pukey mouth.

Reminds me of when a bike race goes bad and you’re always chasing back, spinning out on the descents and gurning on the flat until you just go pop.

Molgrips

Not disagreeing that technique is important (indeed I’ve said this many times on here and been derided for it) but for a lot of people it’s never going to be ‘effortless’..!

I think we are violently agreeing 😉

Just my personal observations though are that striving towards effortless is a good thing in general. Context being many people think they need to “try harder” but they benefit more (running wise) by actually concentrating on “trying less”

Echo the comments above – running is much tougher. But when you run well it feels so serene, I think I get more out of it mental health wise than riding. For me, at least, it’s much more of a solo activity and obviously much more time efficient.

Some say that both running and riding complement each other but I don’t find this at all.

My fitness is at its lowest it’s been for a long time due to a young family and my new job not being feasible for cycle commuting, so I’m taking up running again.

When I was riding several times a week or have me a good cardio fitness level but I’d banjo my legs running harder than they could manage.

Now when I head out I don’t get hung up on pace and can still feel I’ve had a workout in 30 minutes. I expect this will change as fitness and conditioning comes into play though.

Heading out for a 30 minute ride wouldn’t be worth it imo.

I’ve only done trail maras, but 30km+ of hill running takes me to dark places I’ve rarely managed on a bike.

Why not try a nice long MTB ride like the Ridgway Double I did a few years ago. That’ll test out. Still easier on my legs than a half marathon mind.

It depends on what your training objective is. I’d chose running over cycling in terms of weight-loss, but given the higher-impact nature of running it can take a higher toll on your body – so getting the balance in terms of training intensity vs injury can be more difficult. I’m also happier to go out running in filthier conditions – I only have to wash my kit, not clean the bike which can make a difference in winter whether I go out or not.

I guess (all things being equal) running is inherently harder as you are supporting all of your own weight whereas clearly not on a bike.

I think this why a running max heart rate is always higher than a cycling Max heart rate.

I love both but if I had to choose one it would be running I think 🤔 So much less hassle and quite enjoy running in bad weather but cycling in bad weather sucks.

but we’d also lead short 10k or so runs for kick boxing warm ups.

an elite club of Glasgow CEO’s?