Day 21 belongs to the sweet science. The Boxer session runs three 20-second blocks - bouncing jab + cross, bounce + squat + jab + cross, push-up + jab + cross - at 5, 10 or 15 rounds, and every one of them is built around the same idea: punching off a moving base.
The bounce is the ingredient the program has been saving. Staying live on the balls of the feet between combinations is how boxers keep their punches connected to their footwork, and the first block drills exactly that rhythm - bounce, bounce, jab-cross, bounce. The second block adds a level change: drop into a squat as if slipping under a hook, then rise firing. The third block takes the base away entirely and makes you rebuild it - down for a push-up, up to the feet, jab-cross before the stance has time to go stale.
Keep the bounce small and springy - centimetres, not hops - and never let it stop while you are standing. In the squat block, drop under the imaginary punch with the back straight and the eyes forward, and let the rise power the jab. On the push-up block, get up quickly but land in your stance before the hands fire: a punch thrown off crossed feet teaches the wrong lesson. Turn every cross fully from the hip.
Twenty days of striking, and today it all learns to move to a boxer's beat.
Make it Harder: Keep the feet live for the entire round - the bounce resumes the instant you are up from every push-up.
Make it Easier: Take the bounce out and throw every combination from a planted stance.
