Six minutes of clenching. Day 18 is three positions - arms overhead, arms out to the sides, arms straight in front - each held for 2 minutes while the hands clench and unclench without stopping, once through, 30 seconds rest between positions. No sets, no holds with still hands: the card is three pieces, and each is double the length of anything the clenching has asked for before.
The jump is the whole story. On Day 6 each position ran 60 seconds; here it runs 120, and a self-resisted exercise doubled in length is not twice as hard, it is worse than that, because the second minute is done on a forearm that has already spent the first. The overhead position leads as it did on Day 6, taking the hardest hold while the arms are fresh; the side position follows at the longest lever; the front position closes. Each position is two unbroken minutes of squeezing with the arms held out the entire time - grip, forearm and shoulder endurance in a single card.
Keep the pace even for the whole 2 minutes - one full clench and one full open at a time, fingers spread on the unclench, a hard squeeze on the clench. Arms straight and level in the side and front positions, straight up beside the ears overhead. Shoulders down. If the arms sink, lift them back; the minute is long, and the second half of each is where the position is actually trained.
Six minutes of squeezing nothing - the longest the hands and the shoulders have ever worked at once.
Make it Harder: Clench a fraction harder every 30 seconds - the final half-minute in each position should be the hardest squeeze of the day.
Make it Easier: Clench at half pace - one open-close every 2 seconds - and keep the full 2 minutes in every position.
