Lucy_Aspenwind said:Why do these people continue to espouse these views in light of no real evidence in favor of lifting weights and quite a bit to the contrary?
At the risk of making an ass of myself (too late, I know), I'll take a stab at this. Note that I do this as a dyed-in-the-wool opponent of weight lifting for cycling performance; I haven't seen the inside of a weight room in two years, and don't intend to go back until I'm a good deal older.
Consider the "target audience" of Carmichael, Friel, etc. At the risk of over-generalizing, I think the average person plunking down cash for a copy of "The Cyclist's Training Bible" is a male, 35+ cat 3.
Year-round cycling, to the exclusion of all other fitness activities, might present a problem or two for this audience, physiologically. Heavy endurance training lowers testosterone levels. The mid-30's to early 40's is a time when these levels are dropping anyway, and most guys aren't happy about it. Weight-training (and perhaps more importantly, the reduced volume of endurance training that weight-training implies) increases testosterone levels. So, even if you lose cycling fitness by taking a month or two to push around iron, you might be a happier person all around. If enhanced all-around well-being keeps you in the sport for say, five or six more years than you could could handle training year-round, then you might get closer to your genetic potential with a built-in break (to "lift weights", but you could just as well play dodge ball, work on your golf swing, etc.). Even pros have lives outside cycling, and when they neglect them too much they pay the price just like us working stiffs.
Along these lines, cycling is extremely catabolic. Again, guys in their 30's and 40's are losing muscle mass naturally anyway, and attenuating those losses probably translates to a more active, healthier lifestyle in a decade or two.
So, even though weights will not make you a faster endurance cyclist, I think there are legitimate reasons for a coach dealing with the "whole athlete" to prescribe weights. If you're a "mass media" coach like Carmichael or Friel, preaching to lots and lots of frankly inexperienced cyclists, and more experienced, but somewhat older athletes, a blanket recommendation for weights might do more good than harm.