Being in great shape physically is one of the most important factors in the game of basketball. It has been shown on many occasions that when two teams of similar ability compete against each other, it is often the fittest team that proves dominant. That is because, when you are in great condition, everything you do, you can do for longer and better.
Just because you can perform a skill well when you are fresh, or that you can mentally stay focused and execute plays at the beginning of a game, does not mean that you will be able to do those things at the end of the game when you are tired. Fatigue is a horrible thing for a basketball player, or indeed for any athlete, in any sport. You should really think of fatigue as another competitor that you have to beat. If you succumb to fatigue then everything you do deteriorates. You will make more ball handling mistakes; you will throw more bad passes; you will get beaten on defence; you won’t be able to sprint on the fast breaks for easy lay-ups; you can’t ‘get up’ on your shot and you shoot short every time. These are all effects of fatigue, and they are something we must work hard as individuals to prevent.
Fatigue also means less playing time. Your coach will always be able to tell when you are fatigued. It is really obvious to see from the side-line. All of your actions will be labored and your coach will see you cheating and taking breaks on offence and defence. Obviously, they won’t want to take the risk having you out on the court so it is likely you will be subbed out.
Luckily, it is relatively easy to get in optimal game condition. All that is required is some hard work and doing the right drills. It is about making your conditioning game-like, by mimicking the intensity and types of movements you do in a game, and by pushing them to the limit. Having fitness is no substitute for having skills, but if you have your skills in the first place, then by developing your level of fitness, you are optimizing your ability to use those skills effectively for a whole game.