Be water, my friend

I came across this book Fluid BJJ on Amazon…/…/ref=sr_1_1…. The author is a third degree black belt under Renzo Gracie and Jon Danaher, and trains with GSP and Firas Zahabi. In the intro he says: “I believe water drilling has been instrumental in my ability to train seven days a week while continuing to improve my skill set through: mental (imagery) rehearsal which allows me to build up muscle memory and perfect technique while having an ‘easy’ day; repetition/ drilling that does not severely tax my body; and water qualities which improve overall fitness and lower the gravity or training partner’s pressure on my joints”…OK some of it looks like water aerobics, but maybe it’s worth trying