Track and Field Brain Teaser

Update: no solutions yet! I'll post the answer to the riddle at the end of the month after the Prefontaine Classic.
  
One of my great highlights of 2013 leads to this track and field brain teaser:

On the evening before the 2013 Pre Classic I gave Olympic discus champ Robert Harting a ride from the airport in Eugene to his hotel. This marks the 4th time in my life I've given a ride to a world class track and field athlete.

They are, in chronological sequence:

Steve Prefontaine
Rick Wohlhuter
Grete Waitz
Robert Harting.

What unites my four passengers?

I will confess that it wasn't until several months after meeting Harting that the question even occurred to me, much less the answer.

Have fun, everyone!

Mark Cullen
Seattle, WA
University of Oregon '75
www.trackerati.com