100 mi bike ride running equivalent?

I think this thread has popped up recently a couple of times. They're different sports. You can cycle longer with a lower heart rate. If you're a runner, you could build up to a (probably) slow 100 miler in a couple of months. Some cyclists can't run. People who do both sports usually do something like 20-30%. So maybe a 20-22+ run. When I'm in full tri training it's 200+ miles/week on the bike & the running might be 40ish miles/week.

Tried it on Grok and its a bit better

The running equivalent of biking 100 miles can vary based on several factors including fitness level, terrain, and intensity, but general conversion ratios are often used. A commonly cited ratio is:
1 mile of running is roughly equivalent to 3-4 miles of biking.
Using this ratio, here's how you can calculate the running equivalent:
100 miles of biking / 3 = approximately 33.33 miles of running if using a 3:1 ratio.
100 miles of biking / 4 = approximately 25 miles of running if using a 4:1 ratio.
So, biking 100 miles would be equivalent to running somewhere between 25 to 33 miles, depending on the specific conversion ratio you find most applicable to your situation.
Remember, these are rough estimates and actual equivalence can vary based on individual physiological differences, the intensity of the exercise, and environmental conditions.

If you’re point is that it’s not just about muscle groups, you’re right. Running is a lot more calorie-intensive than cycling or swimming mostly because running is weight bearing. That’s why xc skiing is the only competitor.

1/4 rule.

.25 swim = 1 mile running = 4 miles biking

good work tommy

I was going to say about 30 miles based on my own experience but I like yours better

I’ve done bike centuries, half marathons and marathons, and I’d most liken a century to a half marathon - requires some advance training and endurance/grit, but nothing approaching a marathon or a truly competitive cross country race or even 10K race, I’d say.

25 miles roughly but its not quite equivalent because the 25 mile run puts more wear and tear on the legs than the 100 mile ride.

For me, as a mediocre triathlete, the ratio was something like this:

400y of swimming = 1 mile of running = 5 miles of biking for me.

But that is my ratio. I am primarily a runner, so 1 mile of running isn't that hard for me. That's why 50 miles of biking was about the same "effort" as a 10 miles of running for me. For a cyclist, 50 miles on the bike is nothing but a 10 mile run might be impossible.

I swam in HS so 2000y of swimming was kind of like a 4 mile run. It didn't take that much out of me (assuming I am "just swimming" and not doing a real workout). But that is not the case if you are fighting to keep your head above water and learning to breath.

So it totally depends on the athlete. A normal HS swimmer can crank out 6,000y of swimming like it is nothing and that same distance would kill a stud runner like Timothy Cheruiyot.

This is a good post assuming you can swim a normal crawl stroke without stopping. You have to be able to breath and swim with no real effort. If you can do that, that ratio is a good rule of thumb.

Most of us on this board aren't that good at swimming though...

And biking is really easy if you are willing to just stay in zone 2. In zone 2, most runners could go for hours. A lot of cycling is just rolling.

I have never heard of anyone who "burns more calories on the bike" than in running. That seems impossible. Are you time-trialing all your bike rides?

Half of my bike miles (flats and downhills) are low, low heart-rate, zone 2 stuff where I just draft and roll behind other guys. Biking is like an easy day because you are sitting down and can coast whenever you need a rest. Your heart rate is not always as high because cycling isn't a weight-bearing activity. You are literally sitting down.

Cycling is hard when you are climbing or leading the group. But how often are you riding that way? Maybe it is me, I use cycling as a "recovery" from running.

There are too many variables to really quantify this. For one thing, you have bike technology. I have a Madone made for racing that could do 100 miles without any trouble. I also have a commuter bike that weighs 56 lbs. and is anything but aero. A century would be a long day. Running wise, you have super shoes which assist your movement. Someone else could be wearing boots. This is all before you even get into hills and wind, which effect biking quite differently than running, and other variables as well.

Unless swimming is super easy for you and requires like "no effort."

This is one of those things like "dunking a basketball."

Dunking a basketball is basically impossible for 99% of the population. That makes it the "hardest shot to hit" for most people. I can hit some of my 3s and some of my free-throws but I miss all my dunks. But if you can dunk, then it is the highest percentage shot. It is the easiest.

Swimming is like that. If you are bad at swimming, it burns a lot of calories, is super hard, and costs you a ton of energy. If you are good it is only as hard as you make it.

Once you learn the form and the breathing, you can swim with no effort. You just glide along, back and forth like it is nothing. Those people who have the stroke are just cruising up and down the pool on their recovery swims and it is so easy for them.

That is still wrong. Biking allows you to coast all the down hills and draft off of other riders. Even a solo century is way easier than a marathon-50km run. That is just a fact.

AI is not factoring in that one of these activities is seated and allows coasting (still moving with no effort) and the other one doesn't. If you "stop running" during a 50km, you come to a stop. Cycling is not like that. Unless you are just doing a climb, you can coast as often as you want on a bike.

You think a 6 hour bike ride is just as hard as a 4-7 hour run?

That is insane. During a 6 hour bike ride you can coast for 2 hours, draft for 2 hours, and "ride hard" for 2 hours.

During a 4-7 hour run, you have to sustain your body-weight for the whole time and keep pushing forward or come to a stop instantly.

There is not comparison. Go to a "Century Ride" with full support and you see tons of fat dudes on sweet bikes eating muffins at the aid stations. It is too easy to ride a century. It is not comparable to running a 50km to 50 miler (4-7 hours).

Proof - These people are doing a century rides every weekend as their hobby...

Image:www.southbendtribune.com/gcdn/media/20...

5k Sunday pace

During a 6 hr bike ride, you actually never have to ride hard. You can ride easy, as long as it's for 6 hours.

Yes you can coast downhills, but you have to ride the uphill.

Drafting savings overrated. It plays a bigger role in a race, where higher speed causes effect to be greater.

Drafting also does not really make a cycling workout feel easier. A 6hr ride feels like a 6hr ride, whether you were the leader or the follower.

It's like running a 5k, your heart and lungs and calories burnt don't care where you were in the pack and when you made your move.

6 hr ride = 90 min run

Why would ride easy? Put in the same effort as runnning

You can say biking to running is 3:1, 4:1, or more. It all ignores potentially the most important thing, recovery. It could be several days before I'm 100% after at hard 20+ mile run. And I can bounce back from a century in 24 hours. And I'm a relatively terrible cyclist.

All miles are not equal as there is hills, mountains, climbs, wind, etc. I would use time/minutes to compare and effort. A 100 mi bike at 18mph would take around 5 hrs 20 and burn on average 600 calories per hr , so like 3000 calories. Now, a 90min run would burn about 900-1100 total, max. I would be okay the next as I do 90min runs a couple of times a week, but my legs would be dead (maybe not sore but shot) the next day after the 100mi ride. Probably closer to 2.5hr of running = 5.5hrs of cycling in terms of recovery time (like 2 days). Either way 5 to 5.5 hrs/100 of cycling at 18-21 mph would be very hard.