A few weeks ago I played a match against an opponent who had some of the prettiest strokes I’ve faced in a long time. His backhand down the line was downright lethal. Interesting thing was, when we got to the business end of the first set (4-4) his shots went south–he couldn’t find the court. I just passed it off that he was getting tight with the set on the line. But as the match progressed and his consistency continued to plummet, I realized that it wasn’t nerves but exhaustion that was causing his decline. Tennis is a tough sport if you’re out of shape. If your strokes are the engine of your game, then your conditioning is the gas that makes it run. Here are a couple of ideas to help you fill up your tank:

Cross train: Running either outside, or on a treadmill is a great way to build endurance, but it hardly simulates the explosive movements you need on a tennis court. Doing sprints is better, but it’s still not the same–and rather boring. Instead, playing other sports like basketball, squash, racquetball, or even boxing is a more realistic way to mimic the short bursts of speed and energy you need during a point. Plus it adds competition, which makes training more enjoyable.

Lift weights: Some people believe that if they lift weights they stand the chance of becoming overly muscular and inflexible–two things you don’t want as a tennis player. Unless you throw around some serious poundage and consume lots of calories, the opposite is usually true. Lifting weights in high repetitions (sets of 12-15 reps) generally results in getting leaner and stronger. This will help you move around the court, add pace to your shots, and give you more confidence that you can outlast your opponents in long matches.