Zone 3: Power endurance. Pick 4 ~12 move Boulder problems that are ~80% of your max. Starting with your first Boulder, complete it 3 times in a row with a short rest between climbs. You will then get a longer rest befor the second Boulder. You will know the intensity is correct if you are able to complete boulders 1 and 2 but fail towards the end on 3 and 4.