I started walking dry riverbeds and canyons on weekends in my twenties, and I kept hurting myself in the same ways: tired legs on the boulders, weak hands on the scrambles and a wet pack that felt like it weighed twice as much. I was fit for the road and not for the rocks.
Now I coach other weekend walkers on the plain fitness that makes a day in a canyon easier. I teach leg work for boulder hopping, grip and back work for scrambling, how to pack and carry a wet bag, and how to plan around the heat. I teach fitness only. For anything with ropes, jumps or deep water, go with a guide.
What I sell is printed or on screen: a leg sheet, a grip routine, checklists, a training log, an eight week plan and two video courses. The videos are free. What you pay for is the pages you can take to the trailhead and the courses for walkers who want the whole path in order.