Isochain 6x6: 1-rep Max Testing

After several months of dynamic, hypertrophy focused training, I'd been looking forward to strength training on the Isochain. There are a variety of ways to exercise to stimulate strength gains, from calisthenics ("bodyweight-only"), to lifting an external weight, to isometrics. For 2023, overcoming isometrics on the Isochain, under the 6x6 routine, will be my primary exercise for stimulating strength gains. It is the only method I found that delivers strength gains without any concern for the load getting so high that the tendons might be damaged.

6x6 starts with a 1-rep max testing session. I followed the usual protocol, which is to apply as much force as possible, record the max force, rest 1 minute, then repeat until I have 3 force readings, then calculate the average of the 3 readings to arrive at the official score. Results in pounds:

Zercher Squat - 91.73
Shoulder Press - 54.87
Seated Row - 137.8

The only surprise was the Shoulder Press result. I thought the score would be higher, not virtually the same as one year ago. Then I remembered that I was now working with the Isochain bar at a higher position than last year. Last year's position had the arm at slightly less than 90 degrees to the torso, which allowed more of the chest musculature to add force. It was set there because when I was bending my knees more, the arm were closer to 90 degrees. After I realized I should straighten the knees, as part of making the body tighter for the press, the bar position relative to my body naturally went down a little. So it make sense that the force numbers would be lower at 90 degrees. Some trainees only train the Shoulder Press at the low angle, because you get maximum engagement of the chest, and the front delt and triceps are lengthened, which all contribute to higher force output compared to middle or high angle. However, the book Ultimate Isometrics Manual advises spending the bulk of training at the midpoint, and cites a number of reasons.

The midpoint position is a little closer to the edge of of my shoulder pain-free ROM, but pressing is pain-free as long as I protract the scapula and keep the elbows within reasonable distance of each other.