Day 52 brings the hollow hold back with the sit-up now anchoring the session. Fifteen seconds each of sit-ups, knee-in and twist, sit-ups and a hollow hold, at three, four or five sets with a minute of rest.
Look at what the session covers. The sit-up takes the trunk through its full range of flexion. The knee-in and twist adds rotation from a seated position, drawing the knees in while the torso turns to meet them. The hollow hold then removes movement entirely - flat on your back, shoulder blades and legs both lifted, the body held in a shallow curve with nothing touching down but your lower back. Flexion, rotation, and a static hold, in that order, with the hold arriving last because that is when it is hardest to keep.
Come all the way up and all the way down on the sit-ups. Draw the knees fully in on the knee-in and let the rotation come from the ribs. In the hollow hold, press the lower back into the floor first and adjust your leg height until it stays there - and keep breathing.
Sixty seconds of abdominal work that ends with everything switched on and nothing moving.
Make it Harder: Reach your arms past your ears in the hollow hold and rock gently for the full fifteen seconds without losing the shape.
Make it Easier: Hold the hollow position with your knees bent and your hands resting on your thighs.
