Complete bullocks. Just yesterday morning I was in the gym squatting 315lbs, so leg strength clearly isn't an issue for me. I also have the quads to show for it and have trouble fitting into standard pants sizes (always have to size up even though I have tons of room in the waist area). I definitely do have fast twitch muscle fibers and constantly get told I should do track racing.

Conversely Contador is probably the most successful masher among current pros and he prefers to grind the 53T out of the saddle on climbs, and runs standard cranks with a narrow cassette on most alpine mountain stages when the rest of the peleton is on compacts with wide cassettes. Does Contador look like someone who has a lot of fast twitch muscle fibers? I doubt Contador could squat an empty barbell.

Armstrong is on the extreme end of the spectrum and when I refer to spinning I'm not talking about anything close to what he is doing. I can never hold 110+ cadence on the flats muchless on a climb simply in part because I don't have anywhere near the fitness to do and also I'm not comfortable spinning on that level. I'm not denying that people don't have a preferred cadence that "naturally" suits them, I'm simply saying your preferred cadence should be in the 80-110 zone which allows a lot of variance for individual preferences.

There has been successful mashers among pros but they are few and far between and it takes the right combination of genetics, training and doping to pull it off. Its definitely not a model for most of us recreational riders; we're much better off working on our aerobic fitness and spinning in order to go faster/long.

If you're in a gear that you can spin but choose not to spin it, then you're not mashing. It becomes mashing when you are in a harder gear that it is impossible for you to spin. These two scenarios recruit very different muscles but only the former is sustainable for the vast majority of riders.