This is a fair point and I generally agree with you. That said, in this example I'm really using "peers" as a stand-in for where I or someone else in a similar situation will be with little or no regular exercise. (I'm a lawyer in Florida.)
I would expect less ambiguous definition from a lawyer :) (Please take it as a joke)
With the amendment it stands corrected indeed. Just added to make sure some people wouldnt take the idea of comparing themselves to peers as a generally good one.