We have studied 8,495 regular season games in the National Basketball Association over eight seasons (1987-1988 through 1994-1995) to analyze the effects of travel and rest on performance. We found that more time between games improved performance, an effect that was constant over time and statistically significant. More than 1 day between games increased the home team's score by 1.1 points and the visitor's by 1.6 points. Peak performance occurred with 3 days between games. The negative effects of little time between games may be due to lack of time for physical recovery, rather than any effects of circadian rhythm (jet lag). We found few consistent effects of distance traveled or direction of travel. We did find a suggestion of circadian rhythm effects in a subanalysis of games on either coast in which the visitor traveled across the country, while the home team did not travel (n = 101). In these games, the visiting team did four points better (p = 0.07) when they traveled west to east rather than east to west, almost nullifying the home-court advantage. This effect, like similar findings for Monday Night Football games, may be due to West Coast visitors playing night games at an earlier time according to their "internal clock". An incidental finding in our study was that the home-court advantage decreased over 8 years, from about six points to three points (due to relatively lower field-goal percentages and fewer free throws by the home team).