When I turned 40, I decided to try masters track and go back to my “glory” days as a small college long jumper. I hadn’t trained for 19 years. So I started doing some weights (didn’t know what the hell I was doing, using leg press machine, etc.) And I started doing sprints. And I built a box out of plywood to do box jumps of one sort or another. So one day, I put this box out on the infield of my local track and was doing jumps. Well, fatigue led me to finally land on the edge of the box instead of the center. The box flipped, so did I, and I landed on my back on top of it. Since I had not constructed the box very well, it partially collapsed when I hit with me kind of stuck in it. Bruised ribs, bruised kidney, broken wrist, and a shock reaction. Oooooweee that was fun! A guy who had been watching me with wonder or amusement came to check on me. He asked if I needed aid. I of course said no and said I could drive myself home (about 4 miles). He followed me all the way home and explained to my wife what had happened to me. Nice fellow. I am sure there is a lesson in here somewhere.