Day 10 puts you on all fours and picks a leg. Like Day 5, the card adds the change legs line, so the round runs on one side and you swap when you start again: 10 alt arm and leg raises, 10 leg swings, 10 knee-in and extends, 10 leg extensions and a 10-count hold. The alternating raises cover both sides inside their own 10, and everything after them stays on the working leg.
Start on hands and knees with a flat back. Alt arm and leg raises extend one arm and the opposite leg until both are level with your back, then swap, in a stability exercise where the goal is a torso that does not move at all. Leg swings extend one leg straight behind you and sweep it out to the side and back to centre, bringing the outer hip and glute into it. Knee-in and extend draws that same knee in toward the chest and presses it back out, working the hip through its full range. Leg extensions bend the knee and drive the sole of the foot toward the ceiling to isolate the glute, and the 10-count hold parks the foot at the top of that drive and leaves it there.
Keep the hips level throughout, especially on the swings, because the temptation is to open the hip and roll onto one side and that hands the work to the wrong muscles. Imagine balancing a cup of water on your lower back during the alternating raises. On leg extensions, stop when the thigh is level with your back, since anything higher is your spine moving. In the hold, breathe steadily and keep the arms pressing into the floor so the shoulders stay supported.
One knee down, one leg working, and a glute with opinions about which side you started on.
Make it Harder: Lift the opposite hand off the floor during the 10-count hold and balance on two points instead of three.
Make it Easier: Come down onto your forearms for the leg work and leave the hold out.
