Day 17 moves you from lying down to sitting up and back again. The circuit is knee crunches, sitting twists, the dead bug and flutter kicks - 30 seconds each, one circuit, two minutes. No two consecutive exercises share a starting position, which means a chunk of today's work is simply getting from one to the next without losing the thread.
The card alternates between producing movement and preventing it. Knee crunches close the body from both ends, knees and chest travelling toward each other. Sitting twists then lift you upright with the feet off the floor, rotating hand to hip and back while your core holds the whole balance together. The dead bug flips the assignment: lying face up, extending opposite arm and leg while the lower back stays glued down, the job is now to stop movement rather than create it. Flutter kicks end the circuit with small alternating kicks and the deep abs holding the pelvis level against them. Make it, stop it, make it, stop it - both halves of what a core is for.
In knee crunches, curl the hips slightly up as the knees come in rather than only nodding the chest forward. In sitting twists, turn from the ribs and keep the chest tall; leaning back further is not the same as turning further. In the dead bug, slow is the whole point - the moment the limbs speed up, the lower back starts helping. In flutter kicks, keep the range small and the legs straight.
Seated, supine, still, moving - two minutes with no repeated angle in them.
Make it Harder: Keep both legs lower to the floor throughout the flutter kicks, close enough that your heels never rest.
Make it Easier: Let your feet touch down briefly between reps in the knee crunches.
