Day 2 takes the whole circuit to the floor and gives it to your midsection. The two-minute run is: flutter kicks, a raised legs hold, sitting punches, flutter kicks again, leg circles and sitting punches to finish - six 20-second slots, no rest inside the circuit, one minute between sets, at 3, 5 or 7 sets depending on your level. Your abs are on the clock for the full two minutes; the exercises just change what the clock asks of them.
Each slot loads the trunk differently. Flutter kicks scissor straight legs just off the floor while the abs pin your lower back down. The raised legs hold freezes that picture: lying on your back, legs straight and lifted, head and shoulders peeled slightly off the ground, arms at your sides - no motion, just tension. Sitting punches tilt you into a lean-back seat with feet off the floor, and every punch your arms throw is a disturbance your core has to cancel. In the second half, leg circles replace the hold - raised legs drawing circles in the air - which is the hold again, except now it travels.
The technical rule of the whole day is the gap between your lower back and the floor: there shouldn't be one. If your back starts to arch during kicks, circles or the hold, raise your legs higher until it flattens - that is your working range today. In sitting punches, keep the chest tall and turn each punch from the waist, fists snapping to full extension. Breathe through every slot; a held breath is the first sign a hold has gone wrong.
No crunch in sight and your abs will still file this under heavy - two minutes of never quite putting your legs down does that.
Make it Harder: Heels stay off the floor for the entire circuit - including the changeovers between exercises.
Make it Easier: Carry the legs higher, closer to vertical, during the kicks, hold and circles - the shorter lever cuts the load.
