For racing or speed work
This one's intended for the hard-core rider who wants to go as fast as possible, and consequently is cut in a way that is unforgiving of any bodily flaws. This is by design. There is no excess fabric to flutter in the breeze, slowing you down. I have a 35" chest, no love handles, and thin (cyclist's) arms and a medium fits perfectly. But it is a body-hugging fit. If you just like the style but feel self-conscious wearing a shirt that wears like it's painted on, then you may want to size up yet again. By the way, the lightness of the shirt is no joke. A regular jersey's fabric is a canvas tent compared to this. It's just so comfortable (unless you wear them in cool temps--good luck then). As long as you understand the jersey's specific function, you really can't ask for anything better. I think these are supposed to be worn with the body paint shorts, but I'm cheap and wear them with the Endurances. They look uber-sharp & if I didn't have other great kit from Castelli I'd wear these as much as the weather would let me.
Oh. If you wear this on a long ride on a sunny day, be forewarned that you should apply sunscreen to your back or else wear a covering base layer. Unless you like sleeping on your stomach.