For a couple reasons:
1. The writing is much better than RWTB (sorry Lear) yet it doesn't sound like he's trying to impress his college English prof (sorry Mr. Parker).
2. Swimming is harder than running. If some guy is spending a good portion of every day looking at a black line at the bottom of a pool, while going to Stanford medical school on the side, it really affords precious little room to complain about going out for an hour run on a beautiful day.
3. As I mentioned above, one of the protagonists (the reigning world champion in the 200m breast … in a Speedo, not one of those wetsuit things the lads are wearing now) is training to be a physician at the Stanford School of Medicine while he attempts to make his second Olympic team. 'Gold in the Water' offers more encouragement for the student-athlete pursuing excellence in any aspect of life, not just running, and paints a more realistic picture for HS kids – if you're going to do anything in this life, chances are it's going to be by busting your ass 17 hrs. a day in the library studying for Step One like Kurt Grote as opposed to jogging around in Rieti (life is rough!) like Adam Goucher or growing a beard and trying things on with girls at parties like Quentin Cassidy.