For PL II. Not sure how much the chains weigh, but will be weighing them when I get the gym. Not entirely sure what “20% of 1rm in chain weight” mean. If my squat max is 200kg, is my 1rm with chains 160 + 40 kg in chains? How do I calculate RPEs from the calculator with these extra variables.
Most 4’ sections of 5/8" chain weigh ~ 23-25lbs. 20%1RM in chain weight means, only use about 20% of your 1RM in chains. You rate your RPE the same as you would any exercise, based on how hard the set was -typically using the proxy of repetitions in reserve. The chains do not affect how you rate RPE.