On May 12th I set out on an epic journey of running the Grand Canyon from South Kaibab -> North Rim -> Angel Bright in just over 14 hours. Read my personal blog post to get the details on my full experience. Here, I 'm using that experience + my professional expertise to provide some tips and insight for anyone planning their own R2R2R adventure.
Training - I thought the distance would be the most challenging. WRONG! Here are ways I'd advise prepping your body for this run.
Gear - I resisted the urge to take things out of my pack before beginning the run. I didn't and neither should you.
Nutrition - Gels alone just won't do. Be prepared to EAT.
I hope these suggestions are helpful! Good luck out there!
Have questions? Add them to the comment section!