It's amazing how much we lose the ability to move our bodies through space as we age and don't stay rigorously active. I mean, how hard can it be to just lay down and stand back up, right?
I've been working on rebuilding my overall work capacity, fitness levels, athleticism, flexibility, etc. Astonishing how much we deteriorate. Things that look easy and fun(as remembered from our youth) become brutally challenging.
I haven't tried this challenge but I know burpees are really tough on my work capacity. Makes it worse that I carry a lot of anaerobic muscle mass built from powerlifting. I'm tempted to give it a go someday......