Many bodybuilders who retire from competition end up looking like pot-bellied stoves.
That's because they have too much abdominal muscle tissue, and they complicate this condition with a poor diet that makes them add fatty tissue around the waistline.
Retired competitive bodybuilders who want to get their waists down have to adopt better eating habits, which will reduce the fatty tissue.
And they have to refrain from working their abdominal muscles. Training the abdominals will only maintain - or add to - the amount of muscle tissue. So don't train your abs if you want a small waist!