Is this true? I've never heard it before.
historical perspective wrote:
You've never heard it before because he made it up.
But for a runner to improve that system as quickly as possible, than every 2 to 5 days is ideal.
Thanks for your response. Do you have a source on this?
All coaching advice is made up.
I can clarify that statement if you'd like. A runner might be able to maintain their cardiovascular (aerobic) system with a weekly tempo/LT run. But for a runner to improve that system as quickly as possible, than every 2 to 5 days is ideal.
During the track season, some fartlek and track workouts may tax the aerobic system enough to maintain or improve it (and have the same effect aerobically as a LT run).
Really, the runner should max out their aerobic system in the off-season and maintain it during the competitive season. Races and in-season speed work will help develop the runner's lactic acid training (ability to go into oxygen debt during the race and not slow down drastically).
I could be wrong, but I think he is just referring to how, if you don't utilize an energy system every 10 days or so, you'll start to regress in that area...