Day 4 is one exercise and one number: 100 basic burpees with a jump. No levels, no timer, no circuit - the card simply tells you to split the total into manageable sets and get to the end. How you divide it is yours to decide: 10 sets of 10, 5 of 20, 4 of 25, or whatever pattern gets you to 100 without the form falling apart. The rest between chunks is yours to set as well.
The drawing shows exactly which burpee this is. Hands to the floor, feet jump back to a plank, feet jump forward into a squat, and a jump straight up from there - no push-up at the bottom. It is the cleanest full-body cardio move there is: plank for the core and shoulders, squat for the legs, jump for the power, and a heart rate that climbs every time the feet come in. One hundred of them is a genuine challenge whatever the split, and the challenge days in this program are designed to be exactly that.
Plank position should be a straight line when the feet land behind you - hips neither sagging nor piked. Jump the feet in together rather than stepping one at a time, land in a squat with the heels down, and use the squat to launch the jump. Reach up on the jump and land soft. If you are working in sets of 10, the last two reps of each set should look like the first two.
A hundred burpees is not a number you do - it is a number you arrive at, ten at a time.
Make it Harder: Take the total in sets of 20 or more with no more than 30 seconds between them.
Make it Easier: Step the feet back and in instead of jumping them, and take the jump as a rise onto the toes.
