Solve all your warmup/cooldown challenges with this one product from SD. The SD Revolt Recovery Saddle and Seatpost Kit kills two birds with one stone by including everything you need, your race seat and the extended post + seat. A nice padded one at that, and one that doesn't look like you stole it from grandma's 80's exercise bike. 

This complete system is available in the two popular seat post sizes, 25.4mm and 27.2mm, which will cover most expert and pro sizes frames.