Day 20 is a pump day, pure and simple. Four 15-second intervals - alternating bicep curls, lateral raises, alternating bicep curls again, upright rows - for 3, 5 or 7 sets with a minute between sets. Nothing below the waist works today except your patience: the dumbbells stay in hand from the first curl to the last row, and the arms and shoulders trade the load between them.
The design is a tour of the three pulls the program keeps returning to - curls for the biceps, raises for the side delts, rows for the traps and shoulders - with the curls appearing twice as the day's anchor. Fifteen-second intervals suit these movements perfectly: long enough to accumulate real work, short enough that light dumbbells stay honest at speed. By the second half of each set the exercises stop feeling separate and start feeling like one continuous negotiation with gravity.
Alternate the curls with elbows pinned and zero swing. Lateral raises rise level to shoulder height and lower under control - the descent is where the shape is built. Upright rows finish each set with elbows leading and the dumbbells travelling close to your body; if the weights start drifting forward, the shoulders have clocked out and the momentum has clocked in.
Sixty seconds of arms, sixty of rest, repeat - Day 20 is the simplest deal this program offers, and one of the harder ones to keep.
Make it Harder: Curl both dumbbells together instead of alternating - twice the load in the air for the same fifteen seconds.
Make it Easier: When form frays mid-interval, park the dumbbells at your sides for three breaths and rejoin - an honest pause beats sloppy reps.
