# QuestionRunning vs. Cycling: Energy Required

#### Merckx index

I brought up this issue many years ago at another biking forum, and it didn’t prompt much of a discussion, but I’m going to try again. In fact, I’ve seen it discussed at a running forum.

How much energy is required for cycling vs. running? The general consensus seems to be that three miles of riding on a flat route is equivalent to about one mile of running. The ratio or relationship is not exact, of course, and depends on other factors, but it’s close enough for the purposes of this discussion. I will note that the energy required for biking depends more on speed than is the case for running. For example, one source I used said a 165 lb. male will consume about 45 calories per mile at 15 mph, vs. 40 at 12 mph, and 38 at 10 mph. The same source that the same man would consume 130 calories running a mile at 7.5 mph, and actually slightly less, 127 calories, running at 12 mph. This reflects the fact that wind resistance is a much bigger factor at the speeds that cyclists normally attain. But again, the variation is not that important.

OK, here’s the problem. When we consider the actual results of cycling vs. running, the 3:1 relationship doesn’t seem nearly correct. Consider that in a Grand Tour, riders complete stages of 100 or more miles every day for three weeks. Even if these stages were pan-flat, riding them should be equivalent to running 30-35 miles. But in fact most of the stages have climbs, and some of them of course have very steep and long climbs. So they’re energetically equivalent to running more than 30-35 miles. In fact, riders of such stages may consume as much as 6000 - 7000 calories per day. This is equivalent to the energy consumption of someone running 50 miles or more.

But very few people can run 50 miles a day, day after day. There are some ultra-marathon events in which a very small number of people might achieve this over a period of weeks. But we're talking about world record holders. Most runners find it difficult just to compete in a marathon two or three times a year. After running one, they need to rest for several weeks even before resuming training, which is likely to be around 20-30 miles a week. An amateur cyclist, given the time, can ride 10-20 times that much per week, throughout the entire season.

Moreover, just anecdotally, most people who have both run and cycled claim that running a marathon is much more difficult than riding one hundred miles. (I welcome some personal observations here; it may not be unanimous, but I’d bet the great majority of posters would agree with this). Running takes much more out of your body—more muscle damage, ofter accompanied by an inflammatory response—and requires much longer periods of recovery. These recovery periods should come with increased energy demands that wouldn’t be reflected in simply measurements of oxygen use or calorie consumption during or immediately after the event.

Is there an energy deficit that’s made up only by maintaining an elevated metabolic rate for weeks or months after running? I've seen some studies that suggest this, but the results are mixed. Where is the missing energy? Or if there is none, how does one explain the much greater impact of running?

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#### del1962

I think it is possible for a top class distance runner to train doing up to about 120 miles per week, this is not racing and will be at different pace. The difference between this and a marathon race is that every mile in the race is full gas marathon speed, while the training is at different paces. I don't think it would be possible to do a 10k at race pace every day for a week while it is quite possible to run 10k each day for 7 days if your body is trained for it without any adverse effects at a decent pace.

The difficulty with running is that if you up your training to quickly you are almost certain to pick up an injury.

Also there is no freewheeling in running and downhill running puts massive stresses on your body.

Cookster15

#### Alex Simmons/RST

Running involves significant skeletal impacts as well as both concentric and eccentric muscle contractions (in contrast to cycling which has little to no impact forces and only involves concentric contractions).

These factors combine to create additional fatigue and differences in efficiency.

The energy cost of running has also been found to rise as distances get longer / fatigue increases.

#### red_flanders

Running involves significant skeletal impacts as well as both concentric and eccentric muscle contractions (in contrast to cycling which has little to no impact forces and only involves concentric contractions).

These factors combine to create additional fatigue and differences in efficiency.

The energy cost of running has also been found to rise as distances get longer / fatigue increases.
This seems intuitive. Runners just do more damage (assuming no crash for the cyclist) to their bodies and recovery is much longer.

#### MARCOCH

BANNED
OK, here’s the problem. When we consider the actual results of cycling vs. running, the 3:1 relationship doesn’t seem nearly correct. Consider that in a Grand Tour, riders complete stages of 100 or more miles every day for three weeks. Even if these stages were pan-flat, riding them should be equivalent to running 30-35 miles. But in fact most of the stages have climbs, and some of them of course have very steep and long climbs. So they’re energetically equivalent to running more than 30-35 miles. In fact, riders of such stages may consume as much as 6000 - 7000 calories per day. This is equivalent to the energy consumption of someone running 50 miles or more.

#### Armchair cyclist

OK, here’s the problem. When we consider the actual results of cycling vs. running, the 3:1 relationship doesn’t seem nearly correct. Consider that in a Grand Tour, riders complete stages of 100 or more miles every day for three weeks. Even if these stages were pan-flat, riding them should be equivalent to running 30-35 miles. But in fact most of the stages have climbs, and some of them of course have very steep and long climbs. So they’re energetically equivalent to running more than 30-35 miles. In fact, riders of such stages may consume as much as 6000 - 7000 calories per day. This is equivalent to the energy consumption of someone running 50 miles or more.
You forgot the quote marks.

What is going on with these first and only posts that are just randomly selected paragraphs from other forumites posts? Are the Russians behind it?

#### del1962

You forgot the quote marks.

What is going on with these first and only posts that are just randomly selected paragraphs from other forumites posts? Are the Russians behind it?
Nice spot AC

#### King Boonen

You forgot the quote marks.

What is going on with these first and only posts that are just randomly selected paragraphs from other forumites posts? Are the Russians behind it?
I think it's attempts to get round the spam filter.

#### Cookster15

Just stumbled upon this thread. Interesting. As an ex triathlete I am disappointed the thread ran out of gas. Yes running a marathon is much more difficult than riding one hundred miles . Not just the active part but especially the recovery.

Running being weight bearing creates microtears in muscle fibers. Riding doesn't do this. Which is why it possible to conduct Grand Tours but nothing comparable running (apart from the fact no media company will pay millions to put a multi week running race on TV). The human body simply can't repair itself fast enough.

As for the relationship ratio, 3 to 1 is way too low. I read somewhere a long time ago it is more like 5:1. You need to ride 5 times times as long as you run to get the same fatigue (based upon similar intensity, lets say heart rate). That sounds about right from my experience.

#### Tricycle Rider

Just stumbled upon this thread. Interesting. As an ex triathlete I am disappointed the thread ran out of gas. Yes running a marathon is much more difficult than riding one hundred miles . Not just the active part but especially the recovery.

Running being weight bearing creates microtears in muscle fibers. Riding doesn't do this. Which is why it possible to conduct Grand Tours but nothing comparable running (apart from the fact no media company will pay millions to put a multi week running race on TV). The human body simply can't repair itself fast enough.

As for the relationship ratio, 3 to 1 is way too low. I read somewhere a long time ago it is more like 5:1. You need to ride 5 times times as long as you run to get the same fatigue (based upon similar intensity, lets say heart rate). That sounds about right from my experience.
I only just now came across this thread also...

I used to run quite a bit when younger, and I can say there is just so much potential for injury - anywhere from shin splints to muscle tears to damaged knees all from the impact... none of that I've experienced while riding a bike. Unless properly trained and done right it's just much easier to injure oneself while running, and it doesn't even have to be competitive running and hard training. Running is just very jarring to the body, so it's harder and takes longer to recover.

Btw., while a bit of an insane asylum the Letsrun forum is an excellent source on running injuries, every third thread is about someone getting hurt in one form or another and how to get over their injury. It's pretty eye opening.

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Cookster15

#### Cookster15

I only just now came across this thread also...

I used to run quite a bit when younger, and I can say there is just so much potential for injury - anywhere from shin splints to muscle tears to damaged knees all from the impact... none of that I've experienced while riding a bike. Unless properly trained and done right it's just much easier to injure oneself while running, and it doesn't even have to be competitive running and hard training. Running is just very jarring to the body, so it's harder and takes longer to recover.

Btw., while a bit of an insane asylum the Letsrun forum is an excellent source on running injuries, every third thread is about someone getting hurt in one form or another and how to get over their injury. It's pretty eye opening.
Yeh, I suffered from shin splints and then a groin tear that forced me to stop running for 6 months. After wasting time and money on physios my problem was traced to a mis aligned pelvis. After a few visits to a chiropractor the problem was solved and I eventually had my best season the year after. Moral of the story was learn to listen to your body. More and harder is not necessarily better. If you don't recover between sessions you don't improve. Just get injured and/or sick.

Tricycle Rider

#### Tricycle Rider

Yeh, I suffered from shin splints and then a groin tear that forced me to stop running for 6 months. After wasting time and money on physios my problem was traced to a mis aligned pelvis. After a few visits to a chiropractor the problem was solved and I eventually had my best season the year after. Moral of the story was learn to listen to your body. More and harder is not necessarily better. If you don't recover between sessions you don't improve. Just get injured and/or sick.
After a very long hiatus I tried running last year during the holidays because I wanted to see people's xmas lights, it wasn't some crazy pace, it was just some very slow hobby jogging. Still I felt something crack in my ankle, so I was like great, another stress fracture and another 6 weeks of rest. I realized then and had accepted that at my age my running days are definitely over, I really miss it.

It's good your chiro was able to help you, diagnosing a problem can be quite the costly treasure hunt. My chiro did an xray on my achy back and discovered my left femur is about 5mm shorter than my right and I should be wearing some left shoe lift insoles to correct the problem - wait, after about 40 years NOW they tell me?

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Apologies to Merckx i - I have completely failed to answer your questions and musings. Hope you don't mind too much.

Cookster15

#### Black Betsy

I do both, not because I want to, but running is way more easier (and boring, I do rounds in the neighboring dirt soccer field ) and cheaper (a pair of 30 euro snickers per year and a 20 - 30 euro raincoat for those rainy days(forget those overpriced 200-500 endura ones, lol) and reliable ( maybe a couple of 30 euro physio sessions and 40 euro for a medicine for knee pain, in case you're overdoing it, contrast this with the expensive bike components and stuff ). Since I started running 10K daily/60-75 minutes (very early in the morning before work and only 2 hours cycling after work , I feel better and with more money in the wallet to accommodate other stuff.

#### pnwjulial

I brought up this issue many years ago at another biking forum, and it didn’t prompt much of a discussion, but I’m going to try again. In fact, I’ve seen it discussed at a running forum.

How much energy is required for cycling vs. running? The general consensus seems to be that three miles of riding on a flat route is equivalent to about one mile of running. The ratio or relationship is not exact, of course, and depends on other factors, but it’s close enough for the purposes of this discussion. I will note that the energy required for biking depends more on speed than is the case for running. For example, one source I used said a 165 lb. male will consume about 45 calories per mile at 15 mph, vs. 40 at 12 mph, and 38 at 10 mph. The same source that the same man would consume 130 calories running a mile at 7.5 mph, and actually slightly less, 127 calories, running at 12 mph. This reflects the fact that wind resistance is a much bigger factor at the speeds that cyclists normally attain. But again, the variation is not that important.

OK, here’s the problem. When we consider the actual results of cycling vs. running, the 3:1 relationship doesn’t seem nearly correct. Consider that in a Grand Tour, riders complete stages of 100 or more miles every day for three weeks. Even if these stages were pan-flat, riding them should be equivalent to running 30-35 miles. But in fact most of the stages have climbs, and some of them of course have very steep and long climbs. So they’re energetically equivalent to running more than 30-35 miles. In fact, riders of such stages may consume as much as 6000 - 7000 calories per day. This is equivalent to the energy consumption of someone running 50 miles or more.

But very few people can run 50 miles a day, day after day. There are some ultra-marathon events in which a very small number of people might achieve this over a period of weeks. But we're talking about world record holders. Most runners find it difficult just to compete in a marathon two or three times a year. After running one, they need to rest for several weeks even before resuming training, which is likely to be around 20-30 miles a week. An amateur cyclist, given the time, can ride 10-20 times that much per week, throughout the entire season.

Moreover, just anecdotally, most people who have both run and cycled claim that running a marathon is much more difficult than riding one hundred miles. (I welcome some personal observations here; it may not be unanimous, but I’d bet the great majority of posters would agree with this). Running takes much more out of your body—more muscle damage, ofter accompanied by an inflammatory response—and requires much longer periods of recovery. These recovery periods should come with increased energy demands that wouldn’t be reflected in simply measurements of oxygen use or calorie consumption during or immediately after the event.

Is there an energy deficit that’s made up only by maintaining an elevated metabolic rate for weeks or months after running? I've seen some studies that suggest this, but the results are mixed. Where is the missing energy? Or if there is none, how does one explain the much greater impact of running?
I have done both on an off for years, but I honestly have found more physical benefit overall from cycling. Cardiovascular benefits came with me running, but not at long distance runs are more of a HIIT training style of run. With cycling I can easily go up to 20 miles on a bike and not be as worn out. Compare that to running and that is a different story. Although, cycling can also be straining if you have any kind of knee issues, depending on the incline you are going up. I decided to switch and use an e-bike for this, which greatly improved my endurance and ability to utilize my body to the fullest extent while still getting a good workout.