Having worked with numerous tennis players over the years, we've seen how important proper hydration and fueling is because tennis can be such a high-intensity sport that's often played in hot conditions and for long durations.

We've explored some of the most prominent scientific literature and served up recommendations for tennis players who are looking to refine their on-court hydration and fueling strategy...

Contents:

Why hydration matters for tennis players

Every athlete sweats differently. These differences boil down to two factors:

  1. an athlete’s sweat rate
  2. an athlete's sweat sodium concentration

The first relates to how much an athlete sweats and the second to what they’re losing in that sweat.

Tennis is a high energy expenditure sport and players are among the athletes with the highest sweat rates. At the most extreme end, sweat rates of up to 5 litres per hour have been recorded in men and women players. It's not uncommon for tennis players to sweat between 2.5-3L/hr during match play especially when conditions are hot and/or humid. With some matches lasting three or more hours (and potentially even longer in a best of five-set match), total fluid losses can soon accumulate if a player has a very high sweat rate.

Sweat sodium concentration can also differ from person-to-person with some athletes losing very small amounts of sodium in their sweat and others losing lots. This difference can be up to ten-fold (during the course of the thousands of Advanced Sweat Tests we've conduced with athletes, we at Precision Hydration have seen some athletes lose as little as ~200mg of sodium per litre of sweat to others who lose as much as 2,000 mg/L).

An Advanced Sweat Test determines an athlete’s sweat sodium concentration which, coupled with information about their sweat rate, can be used to build a personalised hydration strategy and help maximise performance.

A high sweat sodium concentration and a high sweat rate can result in significant net sodium losses over the course of a match or heavy training session.

Maintaining sodium and fluid balance is key to preventing the development of early fatigue, dehydration, and muscle cramping. Sodium depletion is associated with heat-related muscle cramps. Sodium plays many important roles in the body, not least because it helps the body to absorb and retain fluid in the bloodstream.

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Hydration recommendations for tennis players

To optimise performance, fluid and sodium recommendations should ideally be individualised to a player.

Here's an initial strategy for how to approach hydration before, during and after matches or intense training sessions...

Preload

Players should ensure that they’re starting matches and heavy training sessions in a hydrated state. Preloading is used primarily as a technique to boost blood plasma volume prior to exercise. It is typically used by athletes immediately before very high intensity activity where consumption of fluids is not possible or prior to prolonged activities where sweat losses are anticipated to be extremely high.

How to preload: Mix 1 x PH 1500 electrolyte supplement in ~500ml (16oz) fluid and consume this in the final hours (around 90 mins) prior to exercise.

Ideally an athlete should aim to finish drinking this around 45 minutes prior to the start of exercise. This allows time for the fluid to be absorbed and any excess passed out in urine.

During match play

Fluid intakes during match play should ideally be individualised but as a general recommendation, ~200ml (~7oz) of electrolyte-containing fluid (using your recommended electrolyte strength - PH 500, PH 1000 or PH 1500) should be consumed every changeover (~every 15 minutes) when competing or training in mild-to-moderate temperatures of less than 27°C / 80°C.

In temperatures greater than 27°C / 80°C, players with high sweat losses should aim for less than 400ml (~13oz) each changeover.

Not sure which strength electrolyte is right for you? Take the free online Sweat Test

How to use PH during matches and training: Mix 1 x tablet or sachet of PH 500, PH 1000 or PH 1500 in ~500ml (16oz) fluid

As per preloading, drinks should be prepared correctly to maintain intended sodium strength of drinks (i.e. 1 x tablet or sachet in ~500ml / 16oz of water

The number of servings/bottles per player will vary depending on the duration of play, their sweat rate, and rate of fluid intake (which should largely be dictated by thirst).

As a minimum, athletes should be encouraged to drink at least one serving of their recommended strength before, during and after any training sessions where they have/will be sweating significantly.

When environmental conditions are hot or humid, then a greater number of servings should be recommended but this needs to be individualized on a one-to-one basis because there isn't a ‘one-size-fits-all’ approach.

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Rehydration

PH 1500 can also be used for rehydration in any athlete who's become severely dehydrated or to aid recovery after longer or hotter matches and training sessions. The latter is especially important if a quick return to form is needed (i.e. playing back-to-back matches in a tournament scenario). Depending on the time between rounds and the length of a tournament, match-to-match recovery can vary from as little as one hour up to 48 hours.

The scientific consensus on optimising rehydration in scenarios where a person has become quite dehydrated is that they need to drink ~1.5 times the fluid they have lost. It's also important that this fluid contains plenty of electrolytes to account for the sodium losses also incurred and to help the body retain this fluid. Electrolyte-containing fluids promote faster rehydration than water alone.

The reasoning behind drinking more fluid than the person has lost is to account for the body peeing some of it out (and perhaps continuing to sweat after finishing play). The inclusion of sodium prevents the kidneys from excessively ramping up urine production and just peeing out the fluids being consumed.

How to rehydrate: Mix 1 x PH 1500 tablet or sachet in ~500ml (16oz) fluid and consume it in the hour or two immediately following the activity.

Depending on how much fluid an athlete has lost during play, they may need to continue rehydrating for several hours, especially if they intend to exercise (and sweat) again in the short-term. That said, these fluids should be drunk largely to thirst, and forced, excessive drinking should be avoided.

Fueling recommendations for tennis players

  • 30-60 g/hr of carbohydrate should be ingested when match play exceeds 2 hours to maintain glucose homeostasis and replenish muscle glycogen
  • Commercially available carbohydrate-electrolyte sports drinks offer the advantages of a readily available carbohydrate and electrolyte-rich fluid source. For some players, they could be the preferable option for carbohydrate supplementation during matches played in hot conditions
  • Others may prefer to keep fluids and electrolytes separate to their fuel and opt for real foods like bananas or sports bars/gels
  • The most important factor is that players are taking in enough carbohydrate!
  • When the recovery window is short (<8 hours), it's important for carbohydrate consumption to be immediate on the completion of match play to aid rapid glycogen replenishment

Further Reading