There is some medical evidence that exercise delays the natural shortening of telomeres, but doing a DNA analysis is a pretty expensive and inefficient way to determine if someone exercises. Its probably easier to just look at them and see if they are overweight. But then again, I work out at our gym, so that means I must be a slacker.
A better reason for the PHB to care that his employees will have short life spans is if they have a pension plan, but those are almost extinct these days.
I don't think PHB really has to know short telomeres mean short life span, he just grasps company policy and beats people with it, he's a stress enforcer - another way for insurance guys to cash in. Scott's knack of adding stuff like "slacker trap" is priceless!