Citadel is a full-body strength and conditioning workout built the way fortresses are: from the foundations upward, with every wall doing structural work. Three lunge variations, shoulder taps, plank rotations, push-ups and a pair of single-leg plank holds - nine positions, each one a course of stone. Nothing here is decorative. Everything is load-bearing.

The circuit runs without rest between exercises, and the architecture rises in three tiers. The first row is the foundation, and it's a lunge progression in miniature: 10 reverse lunges establish the pattern, 10 split lunges hold your feet in place and force strict vertical work, and 4 jumping lunges convert it all into explosive power - stability, then strength, then speed, in that engineering order. The second tier builds the walls in a plank: shoulder taps against rotation, plank rotations through it, and 4 strict push-ups. The final tier is the keep - two 10-count single-leg plank holds, one leg raised per side, demanding that the entire structure stay level while a quarter of its support is removed. If the foundation rows were built honestly, the keep holds.

Keep the front shin vertical on all lunge variations and drop the back knee toward the floor rather than lurching forward. Switch jumping lunges in the air and land soft. In the plank tier, hips stay motionless during shoulder taps and rotate as one unit with the arm during plank rotations - the twist comes from the core, not the shoulder. For the single-leg holds, lift the leg from the glute and keep the hips square; the raised leg should change nothing above the waist.

Sieges take down walls built in a weekend. This one goes up set by set, and it isn't going anywhere.

Make it Harder: Extend both single-leg holds to a 20-count per leg.

Make it Easier: Skip the jumping lunges in favor of 4 more reverse lunges and take the push-ups from your knees.