(This is a quote from Karl King, a chemist, race director, veteran of many ultramarathons, developer of Succeed electrolyte products. It discusses running, but applies to cycling.)


"Despite what they tell you in Runner's World, a long run is not for the leg muscles; it is for the endocrine system - a point which has eluded Runner's World authors for over two decades. You can train your muscles by running a 12 mile run every day for an 84 mile week, and be profoundly unprepared for a 50 mile run. However, if you did four runs of 12 and one of 36, you'd have the endurance for most ultras. The difference is that the 36 would stress your endocrine system and force it to adapt for the demands of long distance running. That adaptation is slow to build, and slow to fade, so you don't need a long run every week.

So, Paul's observation is correct. Newbies need the long run work to train their endocrine system. Veterans have paid their dues, so to speak, and can get by with the endurance work found in regularly running an ultra. For example, since Jay has run a bunch of 100s in the last two years, he doesn't need to run over 18 in his training between ultras. Of course, if he didn't run an ultra in three years, he'd lose his adaptation and need to build up again.

A good point is that newbies need to be careful in interpreting how the advice from veterans applies to them. A veteran may sincerely say "this works for me", and since the vet has the adaptation, it does work and seems pretty easy. The newbie, without much adaptation may find that the practice doesn't work for them. Growing and learning are part of the fun of ultra running."