The fifth core day pairs a movement with the hold it creates. The circuit: leg raises, a raised legs hold, leg raises, sitting punches, flutter kicks, sitting punches - 20 seconds a slot, no gaps, one minute between circuits, 3, 5 or 7 circuits by level. The first half is one idea examined from two angles; the second half brings back two Day 2 veterans to finish the job.
Leg raises lift both straight legs from a hover just off the floor up toward vertical and lower them again with control, shoulders slightly raised, arms at your sides - and the raised legs hold between the two raise blocks is simply that exercise stopped partway, legs frozen in the lifted position under continuous tension. Moving through a range and then holding inside it teaches the lower abs both of their jobs in a single six-slot lesson. The back half shifts the workload upward: sitting punches bracket flutter kicks, keeping the trunk stacked and striking on either side of 20 seconds of low, relentless scissoring.
The lower back stays pressed to the floor through raises, hold and kicks alike - if it lifts, shrink the range at the bottom rather than let the arch in. Lower the legs as deliberately as you raise them; gravity does not get free reps today. In the sitting punches, stay tall in the lean-back, feet off the floor, every shot turned from the waist and snapped to full extension.
Raise, hold, raise again - Day 18 is the lower-ab bill for two and a half weeks of training, itemized.
Make it Harder: Make every lowering phase slower than the lift - on every single leg raise.
Make it Easier: Raise one leg at a time, alternating, in both leg raise slots.
