The bench joins the program on Day 5. Three exercises at your level's set count with two minutes of rest: 10 sit-ups on a decline bench with the feet hooked under the pads, a 10-count hold at the top of that sit-up, and 10 crunch kicks performed seated on the end of a flat bench.
A decline does something the floor cannot - it lets the torso travel below horizontal at the bottom of every rep, so the abs are loaded through a longer range and have to start each lift from a stretched position rather than a neutral one. The hands stay behind the head throughout, which keeps the arms out of the equation entirely. The 10-count hold then parks you at the top of that range on already-tired muscle. Crunch kicks move you to the end of a flat bench: sitting on the edge, gripping behind you, leaning back and extending the legs long before drawing the knees back in. With no floor under your heels the legs never rest, and the lower abs carry the whole movement.
On the decline sit-up, control the descent all the way down rather than dropping into the bottom - falling fast on a decline is how lower backs get unhappy. Keep the elbows wide and the chin off your chest. In the hold, sit tall with the abs supporting you instead of leaning back onto the pads. For crunch kicks, keep the chest lifted and the grip firm, extend the legs without letting the heels touch down, and draw the knees fully in on every rep.
The bench adds range at both ends - more distance to travel, and more muscle needed to travel it.
Make it Harder: Take four slow counts to lower through the full decline on every sit-up.
Make it Easier: Do the sit-ups on a flat bench or the floor and keep the hold and crunch kicks as written.
