I'm 5'10 and 155-160lbs athletic and usually wear medium jerseys for every brand I've bought. I ordered a size medium Castelli and when I took it out of the box it literally looked like a toddler size piece of clothing. I was barely able to put my arms through and the bottom of the jersey came up past my belly button... forget about zipping it up. I was determined to have that jersey so I returned the medium for an XL and XXL. The XL fit OK on the arms and shoulder but the torso area was LOOSE..... WTF.

I am certain that Castelli caters to two type of body types..... 5'8, 115lb pro climbers or 5'10 190lb old skinny fat out of shape guys with too much money