Fitness level is not as important as motivation, try to break out of your shell. Because of the nature of the programs many are limited in group size to a handful so the instructors can help everyone. Other programs are limited by vehicle capacity, equipment restrictions or logistics. Sign up in advance to ensure a spot. Questions are expected and welcome. Contact Lance by email or by phone at 208-234-6237. He is often on a river or mountain, so be patient and don't wait until the last minute.
You can rent equipment to go on the river, too.