biking to running conversion

There is no such thing as conversion formulas. People will tell you that x amount of biking equals y amount of running. That is pure guessing. If you´re going to crosstrain you will have to find out exactly how much you can handle and is beneficial to you.

go by hr. usually for me is almost impossible to match easy run hr pace with biking, it would be too hard, thats the main differnece for me

I can still ride 20mph for a fairly long ways (solo) if the terrain is not too hard, and I have left 60-min 10-mile runs way in the past. Of course, I am probably a lot more efficient than you are on a bike and remember when I was first riding that 20 mph seemed fast and hard to maintain for an hour. Of course, it also depends on stop signs/lights etc., because you lose a lot of time with those constraints. Even when you have a bike computer that ''takes out' time when stopped, you have this large time loss coming to a stop, the lag on the computer system, and the acceleration. You can get a sense by riding with someone, stopping as though there is a stop while the other rider continues, and then see how hard you have to work to catch up.

You may have a very inefficient position, which will affect your speed. Of course, as far as getting exercise, efficient position is not really so important. However, while the HR comment is appropriate, you have a HR on the bike that is higher because you do not have efficient muscle patterns etc.

What sort of RPMs do you ride? Do you have 'clip-less' pedals (or toe clips or, much worse, just your foot on a flat pedal. If you have clip-less pedals/riding shoes you should aim to turnover at 90-100rpm, faster turnover than when running.

This would all depend on how efficient you and your muscular system are at handling the demands of biking. If you have lots of experience running but minimal cycling, it would be a more likely comparison than if you had more experience biking than running.

I can ride 20mph for an hour with moderate effort but at my age, I couldn't run a single 6 minute mile.

get used to it.. wrote:

This would all depend on how efficient you and your muscular system are at handling the demands of biking. If you have lots of experience running but minimal cycling, it would be a more likely comparison than if you had more experience biking than running.

that´s true. in my experience the main workload for all runners with strong ambitions must be running. the biking to running conversion is quite disappointing.

We've been over this so many times. The equation should be easy to remember because it's the same as the conversion from rainbows to unicorns

following is the widely accepted distance conversion formula:

b = bike miles

r = running miles

t = time

b ={ [4*(r/t)^2.]/9.4387}*4.38s^2/2m

bikesucks wrote:

For all your x-trainers out there who grinds all of their mileage on the bike, is 20 mph on the bike equivalent to 10 mph(6:00 Pace) of running? I did 20 mph for the last 10 min of my bike workout and got my HR up to 168.

10 minutes at 20mph=6 minute pace? 6 minute pace for how long?

I am a 63 y.o runner turned biker 2 years ago. I can do 68 miles at 21mph with a bit less than 2000 elevation. 3 years ago, when I was in great running shape, there is no way I could run 6 minute pace for a 5k. 6:08-.10 pace yes, but not 6 in races. I can't compare prior to this because I never was a biker but I would say at age 50+ I could equate to running 6 (sub) min. pace for races up to 5 miles.I can only assume that if I biked like I do now then I would be able to go better than 20mph.

1 hour = 1 hour

There is no running - biking conversion - particularly not in mph. No way is 20mph worth 6:00 pace unless in a headwind. 20mph on flat ground, warm weather, smooth blacktop, even on the hoods wouldn't likely be 240w.

In wattage, I find that 245w at 98rpm or so gives me a similar feeling to what running easy in the low-mid 7:00s was when I was running (245w would be maybe 21 mph on the hoods on flat ground and good blacktop at 5000' with no wind and warm weather). My FTP is about 330w right now (the power you can maintain for an hour) but with a running background, my HR and perceived cardio exertion is not as high as at my running AT. I did a 40:00 time trial the other day after a long Zone 2 warmup n 345w (that might be 25mph outdoors with good aero on a road setup) and that was similar to maybe 5:20 pace was running when I was decent. Doing 80:00 at 245w on a bike would be a HR of maybe 123 - a bit lower than 7:20 pace (I live in Colorado).

In cycling, the cardio effort is a combination of power and cadence. Higher cadences get your HR up more at a given power, but spare you leg fatigue. So you can turn out more power in higher gears/lower cadences but can't hold them for as long. If you are new to riding and want cardio fitness, but are fit from running - spin close to 100 rpm to achieve whatever wattage.

Here's a much simpler conversion:

Fastest run for 1 mile or 5k

---------- divide by

Fastest bike for same distance

=x

From then on- bike miles ---divide by x equal run miles.

Ex. 25 min 5 k

----

12.5 min 5 k bike= 2

Then you bike 20 miles easy in 2 hours

----2

= 10 miles easy running in 2 hours

not lance wrote:

go by hr. usually for me is almost impossible to match easy run hr pace with biking, it would be too hard, thats the main differnece for me

yes. HR + time on bike = HR + time running

it's just harder to get the HR really high on biking if you haven't been doing much biking.

MPH isn't a great way to measure anything on the bike due to bike type, hills, wind.

Bike vs running heart rate.

Lots of interesting stuff in the article below:

http://www.runworks.com/2014/02/running-vs-cycling-heart-rate/

For me, a very easy run gets me a heart rate of about 130 (I'm very old with a Max HR of 169), on my spin bike, a HR of 130 feels like a hard tempo run where my HR is in the 155-160 range.

My question is what are you converting?

Calories burned? That's a simple conversion.

Training effect? Not doable. Miles or time on your bike doesn't convert to miles run or time run. Biking benefits overall fitness and aerobic capacity which plays into running fitness, but there's no fixed numerical relationship there, and thus no conversion.

You get into the problem of kids trying to log biking or mowing the lawn as mileage during the off season. Sure, those preserve running fitness better than sitting on the sofa watching TV, but there's no valid "conversion" to running and shouldn't be logged.

If you are injured and cross training, just cross train and log it as cross training if you want to keep a log. If you "convert" it, you are not recording valid data.

There is some conversion. I haven't run a step since August and I know I could go out tomorrow (well, in a few days when my last hard bike workout dissipates) and do a 12 mile run in the low 7:00s at the same HR I always did and wouldn't feel bad aerobically (but my legs would be wrecked the next day). The main difference is the type of muscle contraction. I have gone months riding only to go back to running (thinking somehow a miracle might have fixed my feet) and easily ran a normal speed/volume easy run - only to be so sore I could barely walk the next day and clearly awkward as hell biomechanically and no speed.

If your power and cadence are right, the bike will preserve all your basic aerobic fitness, but your speed will be shot and your bad running economy will make increases in pace more costly in HR than they typically would be.