Health buffs

A group of strangers struck up a conversation on how the maintained their good health.

"Well, i've never had a day's illness, and i'ts all down to a simple , regular life." said one man.

"Between the ages of 20 and 40," he continued, "I was always in bed by nine and up again by six. I worked from eight to five, had a plain dinner and then did an hour of exercise..."

"Excuse me" interrupted another man..

"But what exactly are you in prison for?"