Day 8 belongs to the shoulders. Four exercises at 15 seconds: bicep extensions, shoulder taps, bicep extensions again, side shoulder taps - a minute of arms per set, a minute of rest, sets by level. The bicep extensions repeat deliberately, opening each half of the set, while the two shoulder tap variations move the arms in the two directions the shoulder likes least to be surprised by: straight up and straight out.
Bicep extensions are the fists-to-shoulders, punch-out-to-the-sides move from Day 4, done twice today. Shoulder taps here are the standing version: fingertips rest on the shoulders, then both arms drive straight up overhead to full extension and return - a bodyweight overhead press. Side shoulder taps start the same way, fingertips on the shoulders, and drive the arms straight out to the sides at shoulder height instead. Curl, press up, curl, press out: the same starting position sending the arms in three directions over one minute.
On bicep extensions, tension is the point - squeeze the arms on the way out and on the way back in. Shoulder taps want a full reach at the top, arms straight and beside the ears, ribs down and no lean back to buy height. Side shoulder taps should finish with the arms dead level and the palms facing down; if they drift below the shoulders, slow down and put them back. Fifteen seconds of each is short enough to be perfect on every rep.
Press up, press out - no weight but the arms themselves, and by the fourth interval that is plenty.
Make it Harder: Rise onto your toes at the top of every shoulder tap and side shoulder tap - a full-body reach on every press.
Make it Easier: Run both bicep extension intervals at half tension and save the effort for the shoulder taps.
