Day 8 is 200 climbers, split however you like. Like every challenge day there are no levels and no prescribed rest: the total is the task, and the card leaves the chunking to you. Twenty sets of 10, ten of 20, four of 50 - any pattern works as long as every rep is a climber and the count reaches 200.
Climbers are a sprint done in a plank. The hands stay planted, the shoulders stay over the wrists, and the knees drive in toward the chest one at a time as fast as you can switch them. Reps are totals, so 200 climbers is 100 knee drives on each side. The move loads the shoulders and core as a hold the entire time the legs are running, which is what makes two hundred of them so much harder than running on the spot for the same count - the arms are never off duty.
Keep the hips low and level; if they start rising into a pike, that is fatigue shortening the movement, so pause, reset, and continue. Drive each knee fully under the body rather than skipping along the floor. Breathe in rhythm with the legs. Smaller sets with short rests will get you to 200 with better form than two enormous ones.
Two hundred climbers is one long sprint with a plank holding it together.
Make it Harder: Do the whole total in sets of 50 with no more than 20 seconds of rest between them.
Make it Easier: Slow the tempo to a step rather than a run and split the total into sets of 10.
