I'm not quite sure what you're looking for, can you be more specific? Certainly keeping up with the electrolyte loss and hydration are super important for CF athletes. (I was a competitive runner as a kid, competed and trained horses on the professional level after college for 10 years until my FEV dropped too low). During my competitions, we were clothed almost exclusively head to toe in black, riding during some of the hottest parts of the day, and multiple rides on multiple horses. It was nothing short of brutal. My clothes would crunch from the salt afterwards and my leather boots rotted out in no time. (Yes, riding is very hard work at the top levels). I would sweat buckets, my husband would throw water, gatorade, pretzels, salt pills, etc my way in between rides. I would DIP my pretzels in loose salt, salt every single type of food possible. I just craved it all the time. My body really knew what it needed. The more salt and fluids I had, the better I did. So, really watch those levels.
I second Havoc, daily exercise is crucial to lung health. Make sure his protein and Ca levels are staying high, and best of luck!