Essentially, it looks as if they're compiling all the players who have been reported to be In The Best Shape Of His Life, to see how being ITBSOHL actually improves player's performance.
If you can find ITBSOHL quotes from a reputable blogger/writer, send them to Fangraphs. There is an entry form on the link.
The comments are already getting good, with Leyland's Cabrera comment and Miguel Olivo saying he's in the 4th best shape of his life.
Find a quote, send it in. If it isn't using the exact verbiage, it's okay. Send it in and let them sort it out (imo).