Thanks for the info on getting tested. I think we were having more of a coffee table discussion about it, rather than wanting all the science of getting tested--although you're certainly right about the value of being scientific about it, and about the heartrate monitors (where the differences between running and cycling are rather interesting).

With respect to the ratio question, I still think that 4 or 5 to 1 is too high. This ratio is speed independent. Just as there are the pros in the Tour and there are many serious cycles who don't quite meet those speeds, there are elite runners who pack a 2:10 marathon and there are very respectably fit athletes who need 3+ hours. I don't see anyone organizing events of 20 day, 20 marathons one after another. Sure there are 3-day marathon events and 12-hour runs and so forth. But, someone who holds that 4 or 5 to 1 is correct needs to come up with an argument and evidence to convince me. (And, by the way, 15-16 mph, is a "beginning of the season average" and I was talking 40 to 80 mile rides, not 20.)

Cheers,
Jamie