(The information in this article was taken or adapted from the High Performance Coaching Program Study Guide.)
The nutrient state of a tennis player just before playing or training can have a significant impact on the outcome of a match or the quality of a practice session. Appropriate fat, protein, mineral, and vitamin intake are all important, but the primary pre-match nutritional concerns for all players are adequate carbohydrate and fluid intake. From a nutritional perspective, these nutrients (or the lack of these nutrients) will have the biggest and immediate impact on how a player feels and performs.
Before a tennis match begins, a player’s carbohydrate stores should be full. To ensure this, the emphasis on consuming pre-match dietary carbohydrates ought to begin at least by the previous evening. Better still, a player should emphasize carbohydrate intake over the several days just before the start of an event, and at the same time progressively decrease overall training volume and session duration. This can better optimize a tennis player’s internal carbohydrate stores and fluid/electrolyte balance before beginning a first-round match.
Before play, a player should eat a well-balanced meal with an emphasis on carbohydrate-rich foods and fluid intake (there can be a little protein and fat). Ideally, players should try to eat a moderate-sized meal that contains 2.0-2.5 grams of carbohydrate per pound of body weight approximately 3-4 hours before the match (310-390 grams of carbohydrate for a 155 pound player). By the time play begins, a player’s stomach should be relatively empty, but without feelings of hunger. The recommended number of calories and a permissible amount of protein and fat depend, in part, on when the subsequent match is scheduled to begin. Too much fat or protein can cause digestion to slow down and become too much of a burden.
If play begins 3 to 4 hours after the pre-match meal, players should eat an additional small (0.5-0.7 grams of carbohydrate per pound of body weight), easily digestible carbohydrate snack about 1-1.5 hours before the start of the match. A combination such as 16-20 oz. of a sport drink along with a sport bar or other solid carbohydrate food works well to “top off” carbohydrate stores and body water. Sometimes players are too nervous to eat enough solid food prior to a competition; in these situations, a liquid carbohydrate meal with a little solid food often is better tolerated.
Before the match, a player should drink fluids on a regular basis (beginning at least the night before). This can, of course, include water, but a variety of other drinks can and should be consumed as well – juice, milk, and sport drinks are good options in addition to water. In an effort to stay hydrated, some players drink too much fluid. In some cases, rapid or regular consumption of too much no- or low-sodium fluid (e.g., water) can reduce the sodium concentration the blood (hyponatremia). This can cause problems that range from headaches and nausea to cramps or even death in extreme instances. If a player is using the bathroom every 30-40 minutes, he or she may be drinking too much. If you anticipate sweating a lot during play (and/or you are particularly vulnerable to experiencing heat cramps), extra salt intake (via food and fluid) should be considered.
Do not forget to drink regularly during practice and pre-match warm-ups.