Crossfit workouts times TWO. I did not know it was possible for my upper body and core to hurt so much - workout #2 was 5 kipping pull-ups, 10 (tricep!!) pushups, and 15 'proper' squats, repeat until 15 minutes have passed (or you have died). I could not, for the life of me, do the freaking tricep pushups properly on my feet and ended up having to do back to knees.

but I still did 8 repeats, even though I had to use a purple band for the pull-ups, and no torn calluses!