Running vs Bike riding energy expenditure
 

I am new to Bike riding and doing roughly 20 miles a day 16 mph on a single speed , lots of hills. Switched from running several miles a day after I saw all the knee replacements around me. Bike riding really is fun but all those miles are wearisome, noticed them when I was painting my house. How does bike riding match up to running?

Running rules as far as energy expenditure. Cycling is a refined way to cover greater distance without the energy expenditure of running. Many of us can no longer run. Cycling allows us to get the heart rate up, feel the air, work the lungs, and then after completion of a ride sit back with a short recovery time. Experienced runners have no problem transitioning from running to cycling. As far as energy expenditure, I wish I could still run, but cycling WILL DO!

While running rules in terms of energy expenditure, I think that is when you compare mile to mile. I can do four of five times the mileage of the typical runner out for a hour or two of exercise.

Essentially any comparison should be time based not mileage based.

As a former runner who recently turned to cycling, I can assure you that running uses far more energy. As a runner, one of my goals was to run a marathon (I eventually did five), and when I picked up cycling, I viewed riding a century as a similar goal, which I accomplished last year. It is much easier to ride 100 miles than to run 26. It took me several weeks to recover from my marathons, but the day after my century I was riding as usual. Also relevant to the comparison, I ran my last marathon at age 40, and I was 70 when I rode my century last year.

Mindset change needed, Enjoy the ride > wearisome miles. Fitness benefits secondary.

This is meaningless without talking about pace. What if you rode those 100 miles faster? You can definitely bury yourself over 100 miles on a bike if you want to. It's just easier to cruise on a bike compared to running where you have to put in a fairly high minimum effort to call it running.

Impact forces are a major factor.
There's also how wind resistance scales up when cycling compared to running as far as determining an equal performance.

My goal, in both my marathons and my century, was just to do the distance. I agree that I could have exerted more effort in my ride. So this might be a better comparison. The Tour de France cyclists do 21 centuries in a month. There's no way a marathoner could run 21 marathons in a month.

Tirtha Kumar Phani ran 38 miles a day for 1 year. Stephaan Engels ran 365 marathons in 365 days. He also completed 20 ironman triathlons in one year.

Terry Fox ran a marathon a day (more or less) in the 80's while raising money for cancer. He only had one leg !!
Rare and remarkable but it is possible !!

This only shows that you can pace yourself more easily on a bike. Running requires a higher minimum energy expenditure than cycling. But in either case there is no fixed maximum energy expenditure. Forget about comparing distances because those are irrelevant. You need to compare against time. Does running at your fastest pace for an hour use more energy than cycling at your fastest pace for an hour? That probably varies from person to person depending on how much running and cycling they do. I'm pretty sure I couldn't even run for an hour! But I can hold 300W on a bike for an hour.

if you strain your achilles running, cycling is a good recovery exercise

For me, who rides more than he runs, the maximum energy expenditure per hour is very similar when intensity is matched to produce a similar heart rate.

For instance, riding at 280W which is about my 20-odd minute maximum power, that’s around 1080 kcal expended per hour, my average heart rate discounting the first few minutes is around 166–167 bpm.

Running at 5K maximum pace which is for me is 4:12 min/km (grade adjusted) is around 1070 kcal expended per hour, at an average heart rate once it stabilized of around 166–167 bpm.

Of course, you can coast and softpedal in the draft and plod along on a bike while running requires a minimum effort . Hammer it on the bike without a break and, well, it's no easier metabolically than running, you just don't pound your legs.

It’s pretty logical, anyway, assuming your body is accustomed to both activities, the limiting factor is oxygen and how much you can provide to and burn in the muscles.

My doc mentioned 4:1. Divide bike miles by 4 to get comparable running miles. Obviously there are lots of variables so this is a simplistic (but not necessarily incorrect) guide.

The real question is whether or not you can wear the same shoes running the marathon and then riding the century. Running doesn't really need the protection that a cycling helmet provides, nor does running need a patch kit, spare tube, or a tail light. Biking requires a bike, while running can be done barefoot. A beer run, though, explains which is the better skill. Get out there and do it, as hard as you want to, and don't ever apologize for it.

The answer is 42.

I'm impressed... and stand corrected.

More evidence that running is more taxing than cycling.

I think GCN recently did a video on this topic...

In addition to what has been already stated, at anyone's upper limits, a rider can go anaerobic quite often, and recover while still keeping up a strong pace, this can happen many times in a 'ride', and as long as fuel lasts or is renewed, fatigue takes much longer to set in. I wouldn't have data on this, but from runner friends (distance and marathon), the number of times and duration of anaerobic stints, for runners,are much more limited before a substantial reduction in effort/performance sets in.
ie... Today was the Men's World Championship Road race, 260+ km... with many attacks, breakaways and still most starters finished, quite a few close to the winning rider...
I'm not gonna be a spoiler...
If you want to have some 'number' comparison - here's an Online Power/KCal calculator - gives some workable estimates. Your bike would be 'racing' in the tops, plug in your estimates for your ride numbers, and you're personal stats. You'll have to go to some other sources for running numbers...
Perspective - it's all in the perspective. I found running to be a drone thing... very boring. When I'm riding, even under a strong effort, I'm very aware of my surroundings. Sometimes they go by too quickly, but there's always something which comes through in my peripheral attention. I can ride for hours, and enjoy every minute. If I go for a run; after 15 minutes I'm wondering "when will this be over...?"
Ride On...
Yuri

unless you’re Eddie Izzard - 32 treadmill marathons, 31 comedy gigs in 31 days. Raised STG275,000 for charity 👍

I guess you haven’t heard of Eddie Izzard.
https://en.m.wikipedia.org/wiki/Eddi...rathon_running

The beauty of cycling is that you can go so much farther and see so much more than with running. You probably run the same routes over and over but with cycling you can get a workout in and explore all over your area for the same energy expenditure. I ran for 30 years before transitioning to cycling. With cycling you can get the same workout in the same time you would run if you really dial it up or go climb some steeps. If you wear a HRM for running, do the same with cycling and get your heart rate up til the same level and you will not be disappointed. Besides with running you don’t get the payoff of coasting down a hill and working your butt of climbing.

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.

Probably closer to between 2.5 and 3.5; the faster you run, the closer to 2.5, the slower, the closer to 3.5.

For me yes, running is definitely "harder" because I'm a trained cyclist and don't run at all.
But regarding energy expenditure a quick Google of calorie calculators for running and cycling gives the following results for me:-

Running: 800 calories (80 kg, 7 mph, 1 hour)
Cycling: 1150 calories (80 kg, 20 mph, 1 hour)

The calculator for both activities is here:-

https://keisan.casio.com/exec/system/1350958587

You can play around with the inputs i.e. speed being the main driver. The above calculator suggests I would need to run at 11 mph to match my cycling calorie expenditure. That ain't going to happen!

The obvious thing here is that this result is going to vary depending on your personal running vs cycling speed.
For example if I cycled at 15 mph and ran at 6 mph, then energy expenditure would be identical for both. But I can cycle faster than that, but probably struggle to run at 6 mph for an hour.
Also I can cycle non-stop for at least 9 hours, but there's no way I could run for that long. So total energy expenditure for me is way higher overall when cycling. My biggest ride this year used 5000 calories according to my power meter.