The second chair day grows to three exercises. 80 side leg raises, 40 per side, then 80 back leg raises, 40 per side, then 20 calf raises - all done standing with the chair for support, no dumbbells, no sets. The back leg raise faces the chair with both hands resting on its back, one leg lifting straight behind you and lowering; the calf raises keep the same position, both feet on the floor, rising onto the balls of the feet and lowering.
Three movements, three parts of the leg. The side leg raise works the outer hip as it did on Day 8. The back leg raise moves the effort to the glute itself - the same hip extension as the floor day's leg extension, done upright with the chair holding the balance, 40 on each leg. Calf raises finish with the only muscle the program has not yet touched, and 20 with bodyweight is an introduction, not a test: the loaded version arrives later. Between them the three movements put every muscle from the hip to the ankle through a high-rep, low-load session, which is what a lighter day is for.
On the side leg raise, toes forward, torso upright. On the back leg raise, keep the hips square and the standing leg soft, lift until the glute contracts and no further - a big arch in the lower back is not extra range, it is the back doing the glute's job. Calf raises: all the way up, all the way down, no bouncing at the bottom.
Side, back, up - the chair day triples in size and the calves get their first call.
Make it Harder: The chair is there to take balance out of the equation so the hips can work - keep it, and if the day feels light, add a one-count squeeze when each leg raise reaches its top.
Make it Easier: Halve both leg raises to 20 per side and keep the calf raises as written.
