As a large person you need to pay particular attention to getting hydrated and staying hydrated. This actually applies to anyone, but a smaller person can probably outlast us when it comes to how long before we see major drops in performance because of poor hydration.
“Getting” hydrated is much different than “staying” hydrated. You can’t expect to be in full hydration by guzzling lots of water just before you play.
You must hydrate the day BEFORE you play (it’s a good idea to stay hydrated all the time) and then maintain your hydration on the day that you play.
I started drinking up to 100 oz of water every day. Not only did I feel better and last longer on the court, but I lost 40 pounds too.
Ya can’t beat that! So get and stay hydrated!