What exactly is training to failure? I get so confused by the terms RIR, RPE and training to failure among some others.
My thing is how do I pick a weight where I have zero RIR or 2 RIR etc.
And how do I train to failure? Is it on the last working set? Is it every exercise or just select ones? And what is training to failure, is it after I complete my 8 reps that I continue until I physically cannot push the weight? If yes, isn’t that counter productive by doing high or more reps for legs when the ‘best’ rep range for fatigue etc is 6-8 reps max 10?
Also how do I know how many sets for legs to do? Do I do 5 working sets 6-8 reps etc? How do I know what is enough?