Tennis is a sport played all over the world on grass, clay and other surfaces. According to a study published in the Journal of Sports Science & Medicine, singles competition can burn between 7 and 11 calories per minute regardless of court's surface type. The research continues with suggestions for maintaining hydration and optimally fueling your performance.
According to the study, tennis players need about 3 to 5 grams of carbohydrates per pound of body weight per day to maintain adequate glycogen stores. Men would calculate their needs toward the higher end of that recommendation, while women could get by with less. Suggested daily protein intake is 0.8 grams per pound of body weight, and fat intake should not exceed a gram per pound of weight.
To get the full benefit of caffeine, the study recommends consuming about 1.5 mg per pound of body weight before competition or training. That's 217 mg for a 145 pound athlete. Because sweat rates of a gallon per hour have been recorded during match play, players should start out fully hydrated and try to drink 7 or 8 ounces of an electrolyte-containing beverage during the change-overs. See if this advice adds something to your game.