In-Match Hydration and Fueling for Tennis

Most matches do not end because someone got out-played. They end because someone got tired in a way that changed their decisions. The third set is where bad in-match nutrition becomes visible — the legs feel heavy, the racquet feels heavier, the second serve drops 10 km/h, the eyes track the ball half a beat slower. Almost all of this is preventable with a fueling plan that takes ten minutes to design and three minutes per changeover to execute. Most adult players have neither.

What the body is burning during a match

A competitive singles match at adult club to regional level runs eighty to one hundred and twenty minutes, with rally intensity well above ventilatory threshold during points and aerobic recovery between them. The energetic profile is intermittent — short, high-intensity efforts on a base of submaximal aerobic work — but the cumulative fuel cost is closer to a long run than most players realize. Estimates of energy expenditure for adult singles match play sit around 600 to 1100 kcal for a two-set match, with the upper end common in hot conditions or three-set finals (Bergeron, 2014).

The fuel mix is mixed. Muscle glycogen is the primary substrate during high-intensity rallies. Blood glucose contributes more as the match goes on. Free fatty acids contribute increasingly as glycogen drops. The transition matters because the central nervous system relies almost entirely on glucose, and a drop in blood sugar produces the same symptoms that match-end fatigue presents as — slowed reaction times, poor decision making, reduced fine motor control on the serve. This is not about whether you have enough energy left to swing. It is about whether the brain has the substrate to choose where to swing.

Sweat losses run one to two and a half liters per hour in moderate conditions, three or more in hot ones (Bergeron et al., 2007). Sodium loss varies between players by roughly a factor of three. A “salty sweater” loses electrolytes at a much higher rate, sometimes producing cramping by the second hour even when total fluid intake looks adequate. Knowing your own rate, even roughly, is one of the highest-value pieces of self-knowledge a competitive player can acquire.

The pre-match window

The two hours before a match are the most useful nutrition window most players ignore. The aim is to start the match with topped-up muscle glycogen, normal hydration, and a digestive system that is not actively distracting you.

A practical approach: a meal of roughly one gram of carbohydrate per kilogram of body weight, low in fat and fiber, two to three hours before play. Then a small carbohydrate top-up — a banana, a sports drink, a piece of bread with honey — in the thirty minutes before warm-up. Roughly 500–700 ml of fluid in the two hours before play, sipped, not chugged. If conditions are hot, add 300–500 mg of sodium to that fluid, easiest as an electrolyte tab or a salty snack alongside.

The mistake adults make here is one of two extremes. Either they eat a full meal forty-five minutes before the match — the food is still in the stomach when play starts, energy goes to digestion, the player feels heavy. Or they eat nothing because they are nervous, arrive with glycogen depleted from the morning’s other activities, and run flat by the second set. The middle ground is not exotic. It just requires planning.

What to drink and eat during the match

The changeover is your nutrition window. Ninety seconds, sometimes more. The aim across a two-set match is to take in 30–60 grams of carbohydrate per hour and replace fluid at a rate roughly matching sweat loss — usually 400–800 ml per hour, in chunks small enough to be tolerated.

The simplest tool is a sports drink with 6–8% carbohydrate concentration and roughly 400–700 mg of sodium per liter. This was specifically the formulation tested in match-realistic conditions and shown to maintain performance through three-set duration (Vergauwen et al., 1998). The carbohydrate-electrolyte combination works better than water alone, and better than electrolyte tabs in plain water. The sodium pulls the water across the gut wall faster, which matters when you only have ninety seconds before serving again.

Solids can supplement but rarely replace. A small banana on every other changeover, or a few dates, or a gel — anything tolerated, anything tested in practice before being used in competition. The rule for competition nutrition is identical to the rule for racquets: nothing new on match day.

What does not work: large volumes of plain water (dilutes electrolytes, increases bathroom interruptions, can produce hyponatremia in three-set heat matches); high-fiber foods (delayed gastric emptying, gut distress); high-fat foods (slow digestion); caffeine in untested doses (potential heart rate elevation, anxiety, GI distress). Coffee in the pre-match window is fine if you are habituated. A 200 mg caffeine tablet handed to you by another player on the changeover is not.

The cramp question

Cramping in tennis is a contested area. The traditional model — dehydration plus electrolyte loss — is partly true but incomplete. The more recent literature suggests that exercise-associated muscle cramping has a neuromuscular component, where fatigued motor neurons fire spontaneously, that is not fully explained by fluid or sodium status (Schwellnus, 2009). Both models point to the same practical prevention: address hydration and sodium, but also condition the muscles for the work being asked of them.

The players I have seen most prone to match cramps share three traits: heavy sweaters, salty sweaters, and under-conditioned for the duration they are asking themselves to play. The first two are individual physiology. The third is training. A player who cramps consistently in the third set has, in most cases, not built the aerobic base to absorb the cumulative load. Nutrition during the match is a downstream fix. The upstream fix is conditioning.

That said: when cramping starts mid-match, the practical interventions are increased sodium intake (pickle juice has anecdotal support and some emerging evidence here, possibly via an oropharyngeal reflex), light stretching of the affected muscle, and most importantly, intensity reduction. A player cramping in the third set is at high injury risk if they continue to play full intensity. The decision to continue must factor in match importance, alternative strategies, and the player’s own willingness to risk further damage.

The personal hydration audit

Every competitive adult should do this once, in a typical practice match, in typical conditions: weigh yourself without clothes before the match, record total fluid consumed during play, weigh yourself again immediately after (also without clothes). The weight change plus the fluid consumed gives your sweat rate. Anything over two liters per hour means you under-drank for the duration. Anything under one liter per hour means you can probably get away with less.

Repeat the test in hot conditions if you live somewhere with summer competition. The sweat rate in a thirty-degree match is often double the rate in an eighteen-degree match. The hydration plan has to scale to conditions, not be a single fixed formula.

The other useful self-audit is urine color in the hour before a match. Pale straw is target. Dark yellow means under-hydrated coming in. Completely clear means probably over-hydrated, especially if combined with no morning sodium intake — a setup for low blood sodium that contributes to mid-match cramping in some players.

One thing to do on court tomorrow

Before your next practice match, weigh yourself. Drink only what you would normally drink during play, and keep count. Weigh yourself again after. Calculate your hourly sweat rate. That single number — whether it is 800 ml per hour or 2.4 liters — should anchor your in-match fueling for the rest of your competitive year. Until you know it, you are guessing.

Related in this series: Cardiac Drift and Hydration in Long Matches · Heat Acclimation for Tennis · Sleep for Tennis Players · Match-Day Energy Management

Selected reading:

• Bergeron, M. F. (2014). Hydration and thermal strain during tennis in the heat. Br J Sports Med, 48(Suppl 1), i12–i17.
• Vergauwen, L., Brouns, F., & Hespel, P. (1998). Carbohydrate supplementation improves stroke performance in tennis. Medicine & Science in Sports & Exercise, 30(8), 1289–1295.
• Schwellnus, M. P. (2009). Cause of exercise associated muscle cramps (EAMC) — altered neuromuscular control, dehydration or electrolyte depletion? British Journal of Sports Medicine, 43(6), 401–408.

References

1. Vergauwen L, Brouns F, Hespel P. (1998). Carbohydrate supplementation improves stroke performance in tennis. Medicine & Science in Sports & Exercise, 30(8): 1289–1295. doi:10.1097/00005768-199808000-00017
2. Schwellnus MP. (2009). Cause of exercise associated muscle cramps (EAMC) — altered neuromuscular control, dehydration or electrolyte depletion? British Journal of Sports Medicine, 43(6): 401–408. doi:10.1136/bjsm.2008.050401
3. Bergeron MF. (2014). Hydration and thermal strain during tennis in the heat. British Journal of Sports Medicine, 48(Suppl 1): i12–i17. doi:10.1136/bjsports-2013-093256

Written by Emre Köse Tennis Coach · Beykoz Tennis Club

Tennis coach at Istanbul Beykoz Tennis Club for over 12 years. Graduate of the Coaching Education programme at Marmara University Faculty of Sport Sciences.

• 12+ Years on Court
• Graduate of Marmara University Faculty of Sport Sciences

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