Do you train BJJ when you are exhausted? Does your coach push you to fatigue in warm up so you roll tired? Even though there is something to be said for being able to push yourself to keep going when you are almost completely gassed out, practicing sloppy reps because you want to be fitter is only going to make your BJJ Skills worse. 
JT & Joey dissect this topic and look at it from a few different angles. "Training Tired is training Stupid" If you are early in the Jiu-Jitsu journey you need to put a premium on what helps you learn - physical fatigue won't help. Mental toughness is a key part of rolling and improving at BJJ but trying to practice skills can make your game dumb but tough. If you are someone who likes to go hard on and off the mat this is a good episode for you.

Stay Hydrated with Sodii the tastiest electrolytes in the Game! Get 15% OFF: BULLETPROOF15
https://sodii.com.au/bulletproof

Parry Athletic - Best training gear in the game... Get 20% OFF Discount Code: BULLETPROOF20
https://parryathletics.com/collections/new-arrivals