If you’ve ever exercised in the heat, you’ll know just how important hydration is (especially if you forgot to bring a bottle on your run or ride).

The importance of hydration does not get the attention it deserves.

female athlete staying hydrated with a water bottleFail to hydrate correctly, and you increase your risk of heat-related illness, your sports performance decreases, and your recovery takes a hit. 

And that’s only the beginning. 

This blog post will explain the importance of hydration, touching on pre, during, and post-exercise fluid strategies for optimal performance and recovery.

Key takeaways: 

  • Dehydration is very serious — know the signs to prevent it 
  • Consume fluids before, during, and after exercise
  • Don’t forget your key electrolytes (especially if you’re exercising in intense climates)

Why is hydration so important in sport?

Proper hydration is crucial for athletic performance.

During exercise, core body temperature increases, and the body needs to dissipate excess heat. This is done through sweating and thermoregulation. 

Proper hydration will:

  • Lubricate the joints
  • Improve blood circulation (more oxygen to the muscles and organs)
  • Help regulate body temperature for optimal performance
  • Improve sports recovery

Conversely, a poor hydration status might cause dehydration — more on this below. 

cyclist with helmet pouring water from a bottle on himself to cool downWhat are the effects of dehydration?

Dehydration occurs when your body loses more fluid than it takes in.

You can be dehydrated before exercise, and during — even if you were adequately hydrated before exercising.

One study highlights the side effects of dehydration:

  • Increased body temperature
  • Reduced aerobic performance
  • Increased heart rate & perceived exertion
  • Inadequate recovery between workouts 

Severe dehydration will seriously impair physical performance and is very dangerous. Avoid it at all costs by following the below tips.

How to prevent dehydration

So how do you prevent it?

It’s a simple solution, yet many of us don’t do it — drink more fluids to prevent dehydration.

1.5 to 2 litres of water is a typical recommendation for the day. But if you’re exercising, you’ll need more. 

Drink little and often and know the dehydration signs to prevent it from happening. If you notice darker-coloured urine, or begin to experience headaches, tiredness, dry mouth, or dizziness, then focus on getting in more fluids.

Pre-exercise hydration

A lot of athletes are dehydrated before they even start exercise — this is especially true for those who train in the morning.

At the very least, drink a cup or two of water. 

If you wake up in the night, take a few sips of water. You don’t need to drink excessive amounts, but taking on some fluids during the night is especially useful for morning training. 

If you notice signs of dehydration pre-exercise, you should increase your fluid and sodium intake. An electrolyte mix is always a good option if you suspect dehydration, as this also increases those key electrolytes important for hydration.

You should also avoid sugary drinks before exercise — these may cause a stitch and other discomforts. 

pouring salt electrolytes in a Styrkr water bottle

Hydration during training  

How much fluid you drink during training depends on:

  • How long you’re training for 
  • What intensity you’re training at
  • Environmental conditions (is it very hot, cold, humid, etc.)

For example, if you’re running for less than 1 hour in moderate heat, you likely won’t need to drink anything. Instead, you should focus on pre and post-exercise hydration.

On the other hand, if you’re planning to cycle for 3 hours, you’ll need a hydration strategy on the bike. 

And if you’re running in intense heat or for a long time, a running hydration vest is always a good option.

Related: How to stay hydrated during a marathon

Your fluid needs are individual and depend on a number of factors.

But to calculate how much water and fluids you need per hour, we recommend calculating your sweat rate.

Your sweat rate is how much fluid you lose during exercise/hour (body weight). Aim to replace 50% of fluid loss each hour.

How to calculate your sweat rate

The average person will lose between 0.5/2.0 litres/hour through sweat during exercise. This can be more or less, depending on the activity, intensity, and conditions (how hot or cold it is), according to research.

To calculate your sweat rate:

  • Weigh yourself before exercise (without drinking any fluids)
  • Exercise for 1 hour at a moderate intensity
  • Weigh yourself post-exercise

It’s best to weigh yourself in the nude for accurate results. 

If you weigh 81 KG before exercise, and 80 KG after your 1-hour session, then 1 KG has been lost through sweat.

Divide that by 2, and you get 0.5 KG or 0.5 litres — this is how much you should aim to drink per hour during exercise.

rich gill winning the race

Because you may sweat more (or less) in different sports and climates, you should calculate sweat rates for each sport, e.g. running, cycling, and so on.

Water or sports drinks - what is best for athletes?

Sports drinks are popular because they contain key electrolytes. And they also taste great.

But they also often contain excessive amounts of sugar and calories, increasing your risk of type 2 diabetes, obesity, cavities, and other issues.

During very intense exercise, sports drinks can be useful. The same applies post-exercise.

But usually, salt and electrolyte mixes are much healthier and contain far less sugar.

You might also choose to drink caffeine before or during exercise — this will reduce perceived exhaustion. 

However, before you reach for your favourite energy drink, you might choose to take an energy gel that contains caffeine instead. These also contain easy-to-digest carbohydrates for that extra added bump.

man enjoying the styrkr energy gels during a ride

What sports drink is best for hydration?

During intense exercise, whether a long day climbing in the Swiss alps in the peak of summer or a long run in the heat of California, electrolytes mixed with water are an excellent way to remain hydrated. Hydration tablets are also a great option.

The STL05 Quad-Blend Electrolyte Powder contains key electrolytes to prevent muscle irritation. It’s gentle on the stomach and reduces fatigue so you can go harder for longer. 

You can consume an electrolyte powder before or during exercise for the best results.

Post-exercise hydration 

Hydration does not stop once you’re done with your workout.

Many people forget that you lose water through urine and sweat — your body is trying to return back to its regular temperature post-exercise.

For this reason, once again, weigh yourself before and after exercise.

If you lose 1 KG, you want to drink 150% of this in the following hours. So that’s a total of 1.5 litres of fluids after training.

Do not try to drink this in one go — spread it out over the next few hours.

But when it comes to fluid replacement — what should you drink?

styrkr athlete sam winter indoor training on his turbo bike

What fluid should you drink post-exercise?

During exercise, you don’t just lose water via sweat; you also lose electrolytes (these balance the amount of water in your body and ensure optimal hydration). 

You lose magnesium, calcium, sodium, and potassium — all of which are essential for recovery.

If your workout was very intense, long, or in an intense climate, an electrolyte mix will kick-start the recovery process. But that’s not always needed.

For a regular training session, drinking water should be plenty. But for those harder sessions, aim to increase your sodium intake. Low sodium contributes to dehydration and muscle cramps. 

You can also Increase sodium by eating a salty snack — this may also increase thirst, making it easier to take on more fluids.

But be mindful: excessive amounts of sodium are still related to numerous health conditions. 

What happens if you don’t hydrate after exercise?

If you don’t replace lost fluids after exercise, your core body temperature and heart rate might increase.

You’re more likely to become dehydrated, your physical performance will decrease, and you may find it difficult to concentrate. Your recovery will also be negatively impacted.

A good hydration strategy is crucial to ensure physical and mental performance, not only during, but after an exercise session.

Follow the above tips to avoid dehydration.

Is it possible to drink too much?

Yes! If you drink too much fluid (although difficult, it’s definitely possible), you may create an imbalance between sodium and water.

You’re also more likely to need to pee more often, which is not ideal during exercise.

shop styrkr endurance sports nutrition


Is it dangerous to be over hydrated or under hydrated?

Under hydration (dehydration) is not only dangerous, but it can decrease performance drastically. Overhydration can cause an imbalance between sodium and water — this may cause muscle spasms, confusion, and cloudy thinking. 

If salt dehydrates, why is it used in sports drinks to keep you hydrated?

Too much sodium (salt) can cause hypernatremia but getting the right amount of the key electrolyte is important for proper fluid balance.

What is the best way to stay hydrated without the sugar in sports drinks? 

During intense exercise, electrolytes or a hydration tablet mixed with water is the best way to stay hydrated. While sports drinks contain key electrolytes, they are high in sugar and calories.

Should you hydrate during a workout?

If a workout is longer than 1 hour, very intense, or in hot (or very cold) conditions, then you should hydrate during exercise.

How much water should an athlete drink a day in litres?

How much fluid intake depends on the athlete — how often they train, the conditions they train in, the environment, and so on. Weigh yourself before exercise (and after) and calculate your sweat rate for accurate hydration recommendations.  

What are the 5 benefits of hydration?

Staying hydrated lubricates the joints, improves blood circulation, enhances recovery, helps regulate temperature, and may even reduce your risk of injury.