Endurance Athletes

Endurance training and racing requires quite a commitment from athletes ... the commitment is for time and money ... they put up with pain, they eat for the event and buy supplements that cost a bundle ... their equipment is specialized to their events (shoes, high performance clothing, bikes, skis, wet suit, heart monitor, exercise equipment, etc., etc.) Some of the athletes are in the professional ranks, but most are age-groupers. Why do the age-groupers do it?