Day 20 splits its time between big jumps and a still plank. The circuit is 20 split jacks, 20 high knees, 20 split jacks and 20 plank leg raises - straight through for a set, 2 minutes rest, 3, 5 or 7 sets by level. It is the first day the split jack has framed a circuit in this program.
Split jacks open and return: from a staggered stance, jump and switch the legs so the other foot lands forward, the opposite arm reaching up each time - 10 landings per side in each block, 40 in a set. High knees between them keep the legs running while the intensity drops slightly from a scissoring jump to a run in place. Plank leg raises finish: high plank, hands under the shoulders, lift one straight leg a few inches off the floor, lower it, then the other, 10 per leg. After 40 split jacks and 20 high knees, a still plank with the legs moving one at a time is a change of pace that costs the glutes and lower back rather than the lungs, and the shoulders hold it all.
Land every split jack with soft knees and the front knee over the ankle, and get a full reach overhead. High knees to hip height. In plank leg raises, lift the leg with the glute rather than by arching the lower back, keep the hips square to the floor and the head in line with the spine, and only lift to hip height.
Two blocks of the biggest jump on the card and one block of holding still - the split jacks made the noise, the plank made the point.
Make it Harder: Add a knee drive to every split jack - land, pull the back knee up to hip height, then jump to switch.
Make it Easier: Turn the split jacks into alternating reverse lunges and take the plank leg raises from the knees.
