Haven't read all the post so this might be a duplication. Most recreational cyclists I know were runners first. After their inevitable leg injuries they turned to cycling.

Were those cyclists also people you knew when you were a runner?

I was never a runner. If anything I was a sprinter. Not on the track but playing football or baseball. I was the guy who could steal home. After 100 yds I was useless.

And you can put a kid on a tandem!

You can do 200 watts for hours @ 110 BPM? After a heart condition? I’m seriously impressed (not being sarcastic). My ftp is around 220 and after 8 minutes of that my HR is at least 165. Hmmm. Need to talk to an exercise physiologist……

it’s not necessarily a good thing to have a too-low heart rate, makes each beat harder, the heart enlarges, etc. but yes, I had a couple of years of very steady 50-90 mile rides at that pace, and it didn’t seem too strenuous, I’m fairly tall and swam competitively as a younger person, so the base was probably OK, and the heart condition was originally a rhythm problem, mostly.

things have gone somewhat downhill recently and I’ve noticed it takes about 10% more HR for the same power. and running is just totally out of the question, even if I was being chased 😂

So, there is a lot of wisdom in these comments. At one point in my life, I was a fairly elite runner: Sub 16:30 5k, and running was not my primary athletic pursuit. But! But...I am a cyclist and a soccer player, and those activities give me actual joy. I love playing box-to-box midfield because it makes something in my mind and my soul content. I love cycling fast because it brings me joy and peace and mindfulness.

I don't mean to sound overly hippy-dippy, but what you emotionally connect with is what you are motivated to push hard. If you don't find running enjoyable, then it doesn't matter how good your cardo fitness or leg strength is: You won't push yourself because you just don't care enough...

Rule #42. But seriously, I believe people migrate to activities they enjoy more or can do. I don't think it's fun to run 5+ hours but most centuries I did on the bike were. Even the 30 minute spins was more enjoyable than the group runs that I had to do in the Army.

I seldom run, but when I do, I run just fine. That said, many years ago I ran a lot. Not long distance, just a couple miles, but I ran daily. I think a lot of it is just knowing how. I also hike and backpack - I'm used to foot/earth contact. Everything athletic takes practice.

I hurt my hip stepping in a small hole running the trails at daybreak, so I went from running, to elliptical, to cycling for my cardio. I lift weights the other days.

If I was stuck with only one exercise it would be elliptical. I can set the resistance high and work my calves, upper body, core, and legs then alternate with lower resistance higher speeds and elevated heart rate. Coming off the elliptical the movement gets me in the best cross-fit shape for running on a treadmill or cycling, while keeping some muscle on my upper body and arms.

I enjoy outdoor cycling the most. I like the results of weight lifting the most. I was always hoped my runs would end soon when I was running..

When was the last time you walked up 10 flights of stairs in an office building?

When I was at my peak with cycling, I struggled to climb stairs. I had decent leg strength and cardiovascular fitness, but not enough to get up 10 flights of stairs without an effort. It's one of the reasons I added stair climbing into my training collection.

Older post... but I just had two similar situations with riders I know.

HR is a crazy thing.
One guy I ride with tops out at 120+/-BPM. He's not really fast - when we are riding along at 16-17, his HR is 105 - take it to 18 and he is toast. He gets to 115 and blows up. We've asked him if is HR monitor is borked - its not, he has tried different ones. We've asked him if he's seen a doctor - doc says he is just fine.

Another guy I've met and follow on Strava is a ultra distance senior racer - he does 12 hour time trials at age 68... he always posts his data on Strava. Resting HR of 39, 2.5 hours at 20mph at a HR of 106. Never seen him post a HR of over 110.

Personally - at 54 years old, I've watched videos of pro's putting out similar power numbers as I do at 130bpm. I wonder how we can have the same efficiency at that level when they are so fit... but threshold for me is 145 bpm - 152 is VO2 level, and they are just warming up at that level.

As others point out, cross training is the key. Cyclists aren’t necessarily bad runners. Running is just another discipline that requires its own training and fitness. I run and bike and weight train. In the winter I cross country ski and damned if I don’t discover muscles that get sore doing that ‘cause they’re working in ways different from the other activities. Every activity has different requirements.

OTOH, why do runners make such good cyclists? I've seen runners who seldom ride come out with the group and do just fine in the mountains.