How long could a sub 2:10 Marathon runner bike at 20 mph (32kmh) with 0 biking experience ?

I would never post anything personal here, but I routinely do a 70km or so ride with 900m elevation at 27 km/h on an old mountain bike with thick, knobbly tyres. This is easy, not tempo pace; a little effort, yes, but still easy. Even on that bike on the flat I am averaging over 32 km/h without pushing.

First of all, no one rides for hours @ zero elevation gain. That's like, CRINGE-worthy stuff. Unless you live in Florida, or like ...Norfolk. In which case, your life is already cringe-worthy.

In my area of the USA there is a VERY healthy competitive cycling community. Usually, a 75 mile ride nets you 3-5k elevation. I'd say there are less than 5 guys that consistently post rides at 20 mph or more, and they are working to achieve it. Usually it's a normalized power of 250-300 watts for average build guys. If you're kind of heavy, you can't hang.

Trying to achieve 20 in perfect conditions with zero net elevation is so niche and awkward it doesn't really warrant discussion. It's kind of like going to /r/running and asking if your net downhill mile time trial is 'legit'

much longer wrote:

I would never post anything personal here, but I routinely do a 70km or so ride with 900m elevation at 27 km/h on an old mountain bike with thick, knobbly tyres. This is easy, not tempo pace; a little effort, yes, but still easy. Even on that bike on the flat I am averaging over 32 km/h without pushing.

Unless you have a Garmin/Strava link and can prove you did it on an old MTB, keep your BS off the thread.

Hehe, the aggressiveness/lack of trust here is amazing. I do have a Strava link, and I am not going to post it! Why on earth would I make it up? This is a thread about a completely hypothetical situation that, as you say, would be difficult to replicate in reality. My reason for contributing is simply to indicate what is perfectly possible for a runner in decent shape can do on the flat on a bike without any competitive cycling training; that might be of interest/help to someone. All good runners in my area who cycle a lot are doing 28 km/h average at least on a road bike on standard long rides where there is 1000m elevation or more. They are certainly doing more than 32 km/h on flat segments with no wind.

Couple of points

20 mph on a road bike is not hard, even for an out of shape guy who’s almost 50. I can go out and do it for at least an hour. Granted I pedal around on my mountain bike for 30-45 minutes 3-5 days per week Just to keep from getting fat. I could probably run a 5k in 25 min right now.

In central California, it’s absolutely possible to go for hours and have net elevation gain be less than 200 feet. So for the guy who gets 3k-5k of elevation on an average ride, congrats on living in a hilly area.

Going from running to cycling is easier than the other way around. Years spent grinding away with such a limited range of motion is hard to overcome biomechanically. It’s far easier to learn decent pedaling technique.

Junior year in college I had a stress fracture in my foot so started cycling. Within a month, I was able to ride 60 miles on a rolling road in under 3 hours and had a 24 mile loop I could do in just over an hour, including the first few slower miles while I warmed up. I was in 4:10-4:15 1500 shape at the time.

My guess is that without any cycling a 2:10 guy could ride for 1:30-2:00, but he’s be in a ton of pain. Give him a month and he could go all day at that speed.

Another hypothetical scenario from someone's basement, that LRC is famous for...with a demand for 'evidence'...its hypothetical , the 2:10 guy is not interested.

Way back when I was still around 2:40 shape (later sub 2:30), I used to occasionally take my brother's good bike for a spin when I had a niggle.

45km ride at about 34 on the flat was easy, was almost like a recovery run.

120km loop including lots of hills, in about 31km pace was a good effort.

No...strava did not exist at the time, but could dig up a fun ride result if it exists on web

What type of magical bikes are you guys riding on? When I sub in a bike workout during cross training my goal is 1 hour at 20mph on a stationary bike, which leaves me gassed. To me that feels like an equivalent effort as going out and doing a 10 miler at 5:30/mile.

Anyone who only bikes recreationally a couple times of year would probably get saddle sore after 20 minutes and would probably have some back discomfort around that time too.

xc cancelled? wrote:

What type of magical bikes are you guys riding on? When I sub in a bike workout during cross training my goal is 1 hour at 20mph on a stationary bike, which leaves me gassed. To me that feels like an equivalent effort as going out and doing a 10 miler at 5:30/mile.

They are all full of it.

If he runs a 2:10 marathon does that mean he has to stop. Can't go any further. Maybe he has more in the tank. I had an exercise physiologist tell me three miles of cycling is equal to one mile running. If his life depended on it I think he could go 75 survival miles and not be able to walk the next day.

xc cancelled? wrote:

What type of magical bikes are you guys riding on? When I sub in a bike workout during cross training my goal is 1 hour at 20mph on a stationary bike, which leaves me gassed. To me that feels like an equivalent effort as going out and doing a 10 miler at 5:30/mile.

I've not tried, but maybe the stationary bike has more resistance? Also outside one, on downhills, one either gets a bit of a break or, if one maintains effort, one gets the average speed up.

Just Another wrote:

Maybe up to an hour if he doesn't ride regularly, but he's not going to like it. Hours on end if he puts in a couple of months training. I'm a former cat 1 road racer, so I went the other way, but I can tell you that running and cycling aren't nearly as fungible as many people think. The aerobic capacity carries over, but there's a lot of specific muscles and motions that need to be developed for both sports that have nothing in common.

I knew several former runners who became very good cyclists and vice versa, but you can't just switch overnight. You'll get much better, much faster than someone coming off the couch, but you still need time to adapt.

^THIS^

Finally someone who understands.

Having said that, whether the bike was configured for tt would make a big difference, including frame geometry.

Hard to say. Aerobically, at 20 mph it would like a very easy recovery run. But as others have mentioned, sitting in the saddle for that long would cause problems. FYI several years ago I did a 100 mile race with 6500 ft of elevation gain. Although I drafted 60-70% of the time, I finished it on my $500 road bike in under 5 hours. Although I had some cycling experience, my marathon time at that point was a full hour slower than your runner!

FTP number by itself does not mean much. Your friend could be flyweight at 120lbs, and FTP just below 300W is still pretty damn good (5,5W/kg). Top pros have 6,5 - 6,8 W/kg FTP (1 hour max effort).

I have started biking more in the last year, was never an avid cyclist before, and at 5,3W/kg (still south of 300W at FTP), I am crushing most of the amateur racers. It is not on par with Cat1 best riders, but in the mountains, I am on par with them.

That being said, first few months of riding, 20mph was a good effort, which I could hold for maybe 2 hours without drafting. 15000 miles later, I can do 5-6 hour ride at that pace with 6-8000 elevation gain, without being too taxed. Sub 2:30 marathoner here with very low weight, and better than average leg strength. Thus sub 2:10 marathoner, without insane leg strength, could struggle after 2 hours at 20mph. Not aerobically, but due to lack of specific strength.

i was injured for a week and put 1hr/20 miles a day on the bike for all seven days....upper 17 minute 5k’r ,no big deal.

Sesamoiditis wrote:

Anyone who only bikes recreationally a couple times of year would probably get saddle sore after 20 minutes and would probably have some back discomfort around that time too.

I promise you. i do this every other year or two. over an hour each way. back is never an issue. ass is sore, but not a huge issue. no padded shorts.