Generic the more Upright the posture the wider the back of the saddle .. But the saddle nose between your legs no wider..

In theory A racing bike You are putting weight on the pedals so less on your Butt. and have a strong Set of back & abdominal Muscles. to support the rest of you
taking it off leaning heavy on your Arms. (might want to work on that aerea , gym wise)

A Massage at the end of every days racing is also a Very Nice Thing , amateurs dont get.