Basketball is an intermittent, high-intensity sport requiring strength, power, cardiovascular fi tness, agil- ity, and skill. It is usually played in four quarters with a break at halÅ¿t ime, although overtime periods are necessary if the game is tied. All of the body’s energy systems are used to fuel the sport: adenosine triphosphate-creatine phosphate to jump and pass, the lactic acid system for multiple sprints, and the aer- obic system to support several hours of play. T e game may be played casually or with great intensity and duration and in a variety of venues, from the playground to the National Basketball Association (NBA) arena.Learn more about the sport at the NBA’s website (www.nba.com).