Your BMI is 23. Lance is also 5’10” and his racing weight was 157. So no, you don’t really want to put on weight.

Everyone is different in how they put on protein as their bodies respond to training stress. I’m slow – lucky to put on a pound of protein/year, and hard for me just to keep my thighs the same size. It’s personal. You might be able to lift like a maniac and not get much bigger. I have a noticeable response to weight training – I get faster and have more endurance. Doesn’t seem to matter a whole heck of a lot how I do it: reps/sets, etc. But I don’t get much bigger, if any. I do keep the calories down so I don’t get fat, but if I don’t, I seem to gain fat more than I gain protein. I get plenty of high quality protein in my diet, so it’s not that.

However, I never put much time into weights: 25 to 45 minutes once or twice a week. More than that, and it takes away from my cycling, and that sure as heck doesn’t make me faster. Hours on the bike is what really makes me faster. I fit in the weight training around that, and make certain it’s not interfering.

Fast riders I’ve known have sometimes gotten sidetracked into joga and the like, usually a female influence, never a bad thing, but it made them slower, not faster. So it’s a whatever you want most kind of thing, same as big muscles and all the rest of it. It’s quite clear that intervals and getting light, down to a BMI of around 19, makes one faster. The rest of it is not so clear.

BTW, I don’t think it has anything to do with fast vs. slow twitch muscles, and more to do with with the precise training modality: range of motion, force distribution within that range of motion, speed of the movement, time spent with muscles contracted, percentage of muscles used in sport movements which are stimulated, etc.