The trend I see is that they have 100s, and sometimes even 1000s of hours in patient contact experience and/or non-clinical volunteering (as the Russians would say, quantity has a quality on its own"). Many were in the categories listed by
LizzyM, although I personally have never interviewed an Olympic level athlete (although one of our recent grads was one...she's now in residency at a Really Top School's university hospital). Never seen a pro athelete either.
A few venues that come to mind were writing policy papers or lobbying on public health issues; work with the homeless or other disadvantaged populations; extensive teaching.