[christopher.howitt]

This is my first post on the forum, and I wanted to start by thanking Steve and Scott for the fantastic resources they are making available. I don’t think there is anything else out there that teaches recreational / amateur athletes the science behind training in such a clear and methodical way and it has certainly been eye opening for me.

My question concerns the “transferability” of one’s aerobic fitness over different activities. Or to put this another way, the extent to which the aerobic capacity one has in one activity (e.g running) overlaps with the aerobic capacity one has in another (e.g. cycling). I ask because running is my main sport, but I cannot do more than a few miles a week currently owing to a knee injury. I am able to cycle however and am enjoying going out on long Z1/Z2 rides. Ideally I would like to build up my base through cycling, while slowly increasing the running milage as my knee recovers – so that my running engine is much the same as before I got injured. But I was wondering how much crossover there is – i.e. whether there is ultimately a cap on the benefit I can get training this way, so I would be better off waiting and building up running-specific fitness as my knee recovers.

Any thoughts would be much appreciated.

Topic

[Steve B]

Steve B on May 10, 2020 at 10:42 am #41472

I’m not an expert, but I do know that cycling supports running better than running supports cycling. From my own experience, I can easily transition from cycling to running, but not the other way around. I think it has something to do with the type of strength you can build cycling. I have been riding a ton lately, and no running at all. Likely the half marathon I have coming up will be postponed, but if this not we will see how the experiment goes since I will not run at all before the race and hope my cycling can carry me through the race.

[Dada]

Dada on May 10, 2020 at 11:28 am #41482

To sum up my knowledge I have gathered from this forum so far:

– cycling is good but not as intense as footborne activities -> so 1 hour of Z1/2 corresponds to 3h of cycling in the same zone

– your AeT for cycling will probably be lower since you only use a smaller percentage of your body muscles -> e.g. my AeT for running (165) and cycling (150-155)

– cycling out of the saddle is superior to sitting when you train for running

Have fun and get well soon.
Dada

[christopher.howitt]

christopher.howitt on May 10, 2020 at 12:29 pm #41486

Thanks both. That intensity ratio (3:1 cycling:running) reflects my experience too. What I would be curious to know is where that intensity is felt – is it that the aerobic engine is working less hard on a bike, or is it because on a bike you avoid the pounding the muscles get when running? In any case it looks like there is limited benefit from putting in many low intensity training hours on the bike.

[Dada]

Dada on May 11, 2020 at 1:08 am #41504

You avoid pounding your muscles.

Take a look at Stephan Seiler’s presentation: https://www.researchgate.net/publication/310725768_Seiler%27s_Hierarchy_of_Endurance_Training_Needs

There is a sample calculation of running vs. Rowing. This also holds for cycling.

Cycling is still very good, but you need high volumes. A little anecdote from yesterday: I was cycling the first time this year and before just training hiking and running. I could stay below AeT the majority of the time but I was still tired after the 2.5h. More tired than after 1h running at AeT. I think it’s from the fast and continous motion.

Dada

[christopher.howitt]

christopher.howitt on May 11, 2020 at 6:02 am #41512

Great link, thanks!

With cycling I think it depends on the terrain – where I am is relatively hilly, so you are either climbing or rolling down on the descents – so effectively resting 50% of the time.