grueling and 40-day seem a bit incongruous. That is, after crewing RAAM, which does around the same distance in six days...
You might want to see "Bicycle Dreams," which is about the RAAM solo race.
I'll check that one out. I read Hell on Two Wheels, which is about RAAM. The toll that one takes on the body is nuts. Six days or 40 days...they're just a different kind of grueling.