How much does running fitness correlate with cycling fitness?

Leg muscles used are much different. Cardio-wise a runner transitions well. How well did Webb do on his bike portion of his tris?

I can tell you from personal experience.... Not good. I have participated in a 40K bike time trial off of basically zero bike training right around the same time I was in 15 minute 5K and 2:30 marathon shape. I finished the TT in exactly 1 hour (25 MPH average). The fastest guys beat me by a good ten minutes. No excuses. I rode a good bike (Cervelo P2 with 60MM SRAM Wheels). The only thing I would say would have significantly helped was having an aero helmet and body suit which I did not. Being generous these two things probably would have dropped me down to 59:30? So still way behind.

Aerobically the race was cake. But my legs didn't have the power to turn a bigger gear. Outside of you benefiting aerobically from running your leg strength doesn't translate very well to cycling at all.

The technical bike handling skills, strategy, and team dynamics in cycling are vastly under-appreciated by most runners. It is very often the case in amateur bike racing that the strongest rider does not win the race.

I knew a recently graduated collegiate 29:30 guy who showed up to some local races and thought he could just ride away from everyone...the pack would chase him down every time, then a team would counterattack, a break would form, and the collegiate guy was left behind in the pack with everyone else. Cycling is a sport where there are plenty of experienced guys in their 40's and 50's who can hang with and beat far younger and fitter inexperienced riders.

One place you can do well is on long climbs.

DFT wrote:

I can tell you from personal experience.... Not good. I have participated in a 40K bike time trial off of basically zero bike training right around the same time I was in 15 minute 5K and 2:30 marathon shape. I finished the TT in exactly 1 hour (25 MPH average). The fastest guys beat me by a good ten minutes. No excuses. I rode a good bike (Cervelo P2 with 60MM SRAM Wheels). The only thing I would say would have significantly helped was having an aero helmet and body suit which I did not. Being generous these two things probably would have dropped me down to 59:30? So still way behind.

Aerobically the race was cake. But my legs didn't have the power to turn a bigger gear. Outside of you benefiting aerobically from running your leg strength doesn't translate very well to cycling at all.

If you can do basically no bike training and ride 1h flat for a 40k TT, the running fitness has helped you a hell of a lot! Your average person who does no bike training or running would ride 1:30 for a 40k TT.

25mph time trail is pretty darn good, haha. I don't really believe you about the "basically zero training" because who would have a Cervelo P2 and not use it? lol.

Obviously, different muscles are used at different intensities, but I believe a lot translates from one sport to another. I don't think there is any 1 to 1 correlation you could make from running to cycling, but it definitely helps.

Ghost of Cannell wrote:

The technical bike handling skills, strategy, and team dynamics in cycling are vastly under-appreciated by most runners. It is very often the case in amateur bike racing that the strongest rider does not win the race.

This needs to be repeated in every future thread comparing these two sports. I am a runner turned cyclist and I can't tell you how many times I have to explain cycling tactics to my runner friends. They just don't get it.

Run to bike there is good correlation

Bike to run, not much

IMHO

zero

specificity

I didn't think I did that well at all. I was middle of the pack in the slowest class.

I had just bought the bike no more than 2 months prior to this race and had maybe 200 miles on it prior to the race. I was still running everyday so I hadn't done a block of bike training, I did no more than 3-5 hard rides/workouts on the bike prior to the race. Definitely not enough to say I had legitimately trained for it. If I'm honest I still haven't used the bike nearly as much as I should. Mainly because I still run everyday and cycling training is a massive time suck.

Here is a link to the results if you care to have a look. The class I raced in was Men Cat 5 Senior. I was 5th. The fastest guy in Cat 1 destroyed me. He rode 48:33.

https://www.road-results.com/race/1873#cat17143

The Cat1 guy was close to a professional level, as he became a Cat 1 by beating pros, and other Cat 1s and Cat 2s. As a 15:00 min guy, you're nowhere near semi-professional or even a shoe-sponsorship, so it's really not a fair comparison.

Though I agree that no matter how fit of a runner you put on a bike, they'd get dropped easily by even a mediocre athlete who has trained as a cyclist for a year or more. I don't care if it's a 5'9 165lb 14:00 guy, he'd get dropped by pudgy 50 year olds with no specific training. A few months later might well be a different story, but it's not necessarily the running fitness helping, rather the fact that a 15:00 min guy simply has a high natural ability for endurance, and that's certainly helpful in other endurance sports too.

I think that if you can become a decent runner after years of training, you could probably become a decent cyclist after years of training. Someone who can't break 19 minutes after serious training on the other hand, either has serious biomechanical issues or simply a lower endurance ability, and I wouldn't expect them to become a great cyclist. There's tons of (lightweight) pro cyclists who wouldn't break 18 minutes without spending a few months training for it.

How much does swimming fitness correlate with running fitness? A great swimmer would probably run a faster mile than some random guy off the couch, or even your random guy from the high school track team. But you wouldn't expect Phelps to run 5:00 off the bat, and the situation with cyclists isn't too much different.

Even if the bike race is a time trial where the complex tactics of bike road racing don't come into play, I'd say the correlation is very low. Yes, both require excellent aerobic capacity and leg strength, but as other posters have said, the leg muscles are used very differently. I am a runner and recreational cyclist and my husband is a bike racer and occasional hobby jogger. I cannot even stay in his draft on a bike unless he slows down to a pace at which he feels ridiculous, but I can hardly jog slowly enough to run with him.

I also have a very hard time believing that anyone with no cycling training can ride 40K in an hour. I have run 2:18 for the marathon and my 40K after a full year of cycling was 1:13:xx.

Agreed. Probably not fair to compare myself to the cat 1 guys, but I was beaten pretty badly by guys in all categories, even my own. I'm definitely not anywhere close to professional level as a runner but if I hop in just about any race in my state/region I will finish near the top of the results list. Whereas if I enter a bike race around here I'm at the bottom of the list, and that is in a time trial where skill in bike tactics isn't a factor.

Also agreed, it doesn't matter how good of a runner you are it will take some time and serious training to switch over to being good on the bike (no guarantees you'll be an equally strong cyclist as runner either). Runners come in with the benefit of aerobic development but as far as muscle development they can expect to have a lot of work to do.

I remember the only person I was able to pass during the race happened maybe 5 minutes in (stagger was 30 seconds I believe). That same guy ended up trailing me by around 20 seconds the rest of the way. He rode up to me afterwards to say nice race. Couldn't believe the guy was in his mid-50's.

Running translates well to biking.

But as a runner, you will do much better if you are at least familiar with things like aerodynamics, shifting gears, maintaining momentum, riding at higher speeds, taking corners, etc.

For pack racing, tactical awareness is important.

Also, not all fast runners are quick cyclists. Highly efficient, lightweight technique type runners do relatively poorer at cycling than bigger strength type runners. The technique runners have the aerobic fitness but not the power. Runners that do better at hilly cross country will do relatively better at cycling.

And runners tend to do well on long cycling climbs. They have a good power to weight ratio.

I would say a 15/5k or 2:30 marathoner would be very competitive as a Cat 3. and should be at least Cat 2