In grappling sports, if get to a point where you can't grip anymore you are in trouble. It basically feels like running out of ammo in a gun fight. If you can't grip, there is not much you can do. When the forearms get pumped with lactic acid, it gets very troublesome to keep holding on. Building just a strong grip is not enough and athletes should work on building a grip that can also last. There are various tools to work on building a long lasting grip and exercise in video below is a great tool to add to your grip repertoire training. Judo legends such as Jimmy Pedro were known for training the grip and the importance of this for grappling. Primal steelbells or similar products are great for this exercise.