Yup, and eating right. What kept tripping me up in my 20s as I tried to get back into shape time and time again was learning that I couldn't eat like a teenager any more. I have to be really careful what I eat. I eat nutritious food now wherever possible. I throw in 3 1-hour visits to the gym during a busy week and 4 if I have the chance.

It does give me self-confidence. It also helps me think more clearly, handle more stress under pressure, and since most of my friends are at the same gym we get time to socialize during the week. It beats spending money on booze to socialize at a bar with friends during the week. Save that experience for the weekend :-)