Does 1 mile on stationary bike = 1 mile of running?

1 mile of running equals 3 to 4 miles of biking.

I don't believe there is any perfect conversion formula out there but I have seen many references to a 3 to 1 ratio of biking to running. I am skeptical of that though, because I'm able to get my HR way up on the bike, similar to running. I don't overanalyze it , I just know that whatever I do on the bike is a good workout, either as a supplement to my running or to help maintain fitness when injured.

A person rides much faster than they run, so distance comparisons are ridiculous.

But, in terms of aerobic fitness:

5 mins at 130bpm HR on a bike is equivalent to 5 mins at 130bpm HR while running.

Running performance is not solely about aerobic fitness though. There are particular neuromuscular adaptations that take place through running training that make one a better runner.

Some stationary bikes measure distance in ways that makes it completely worthless:

Like [RPM x constant x time] where the constant is the wheel's circumference. You could push 400w or 80w, but as long as the RPM stays the same you go the same "distance".

The only things that matter on the stationary bike are wattage and time.

No! Not even close.

I usually consider 10 minutes of moderate effort riding to be equal to 1 mile of running for my own purposes of logging training.

Have to be actively pedaling and not just doing it while focused on something else.

Most of these answers seem reasonable. Mileage-wise, it's around 1/3. But heart rate & power matter. Spinning & running an hour with the same heart rate is going to be pretty similar aerobically. That seems to be your question OP. If you're injured or are replacing a run I wouldn't automatically do the mile conversion & say that you need to do a 3 hour ride to equate to a 1 hour run. You're probably ok doing an hour or something like 80-90min.

You should be somewhat careful depending on what kind of bike you're using because some of them really do get the heart rate high -- higher than it would be outside because of the resistance. Plus if you don't have a set up with a fan it might be toasty & you might be sweating at a decently high clip.

Strangely worded question coz being able to go one mile on foot (at all at any speed) requires more aerobic fitness than riding one mile on a bike, but how much more depends on the foot and pedaling speeds being compared.

For most people, at the same RPE, biking has a few beats/min lower HR compared to running.

My HR on stationary or mobile bike never comes close to my running HR, no matter how hard or fast I am going. I'm not a good cyclist, but have rode over 100 miles at a time. It was tiring but more because of boredom than anything else.

Close but a harder effort on the bike, such as on hills while maintaining a lot of watts, into a headwind with a lot of watts, etc, will be lower than the 1 mi running to 3-4 miles biking. More like 1:2 or, potentially, lower.

Stationary cycling isn’t even close unless high resistance is used.

Yea I agree miles are problematic. I guess it completely depends on the effort of the bike mile? So, yea, I would agree with HR and minutes. One caveat- I give myself a little leeway on the bike HR, as it seems you have to go extremely hard on the bike to = the same HR as a somewhat hard run.

One mile of running = one mile of running.

Yeah I have no trouble getting my HR up on the bike but it does seem to take a bit more focus than running.

Anyone who has done extensive cross training on the bike also knows that you can workout harder more frequently than running. I sometimes go through stretches of 4 days in a row of medium to medium/hard intervals on the bike with zero recovery issues.

I think simply tracking HR and minutes is the way to go, unless you have an accurate power meter.

I mean...doesn’t it entirely depend on the resistance the bike is set at, the speed you’re pedaling, and the speed at which you’re running?

Divide bike distances by three.

Multiply swimming by four.

e.g.

A 30-mile ride is like a running ten-miler.

A 2500m swim workout is like 10k of running.

3:1 on the flats, 4:1 conversion on the hills for the bike.

Try a warm up, then a one-hour time trial on the bike and a cool down. That's a perfectly painful way to grind out a very hard effort in a concentrated period of time. Aim for as much resistance as you can muster while maintaining 100 RPM or just a hair over. That seems to be a magic number for power and efficiency.

1 mile of running ~ 100 cal burned

1 mile of cycling at a steady pace ~ 35-40 cal burned

You do the math

I don't think calories should be entering this discussion at all, unless we're talking about fueling for longer rides/runs.

As other posters have already commented, equivalent times of each at similar exertions can be considered similar aerobic training stimulus.

As an aside, I'm a strong cyclist and a poor runner (I do a lot of riding and zero running), so I don't think any strong runners would be able to complete my hard cycling workouts, just like I wouldn't be able to complete even fairly easy workouts of good runners.

I probably do similar amounts of running and cycling now. Its hard to track training load well - I use a website called intervals.icu which I think tries to normalise effort on bike (with power meter or heart rate) and running (by heart rate).

Its only a guide though and I think relates to aerobic load only - the muscular damage from certain running (e.g. very intense intervals) isn't properly taken into account.