Even Short Intervals Have Tremendous Benefit

[Wahine]

The 220 minus your age thing is well known to be inaccurate in many populations, especially trained athletes. So it's always better to do an empirical test to find out what your max HR is.

The science behind not having to run (or ride) great distances is that what we're trying to do with our long workout days is develop our body's ability to efficiently use fat as our primary fuel source. That requires pacing. So most exercise physiologists seem to agree that the benefit of going longer than 2.5 hours (for running, I'm not sure what the suggestion would be for riding) is minimal in terms of training your physiology. However, it can be very important for some people psychologically.

Lime, I did a 100 mile MTB last year. My longest rides were 5 to 6 hours typically and then only once per week. I did one really technical 50 mile race that took me 8 hours. My 100 miler ended up being 108 and it took me 16 hours in the end. The one thing I would say is that my postural muscles (back and neck) were seriously challenged by being in the saddle that long so I would strongly recommend doing consistent postural muscle strengthening to prepare, especially if you don't think you'll get that many long rides in.

[limewave]

The one thing I would say is that my postural muscles (back and neck) were seriously challenged by being in the saddle that long so I would strongly recommend doing consistent postural muscle strengthening to prepare, especially if you don't think you'll get that many long rides in.

That makes sense and that never crossed my mind! I'll be sure to work something into my routine to prepare for that!

[OakLeaf]

I read recently that one of the strongest predictors of hitting "the wall" in a marathon was not having done a training run longer than 20 miles. That's way more than 2.5 hours for me (especially at training pace!). I could only find an abstract but it looked like it was mainly focusing on psychological factors.