Good point. I don’t periodize my BJJ training, but when I am tired and sore I go light. I like an undulating periodization model for both cardio and strength work. Rest and knowing what the precursors to overtraining are like are huge. My “limit” training is what I can maintain year round. Base training as it were with smart full breaks here and there. I have read way too many books on strength training and running, used to run ultras and lift a lot before embracing martial arts. Undulating periodization basically works out to a few different training intensities and modalities that are cycled through carefully to promote stimulus and avoid overtraining. It’s similar to block periodization in concept to block periodization but the blocks are more flexible and at my age much shorter before I have hit the max benefit of a block and moved on to the next one. The cool thing about undulating periodization is you pick up where you left off in a block.