Hydration Tips for Runners: Includes How to Prepare for Race Day

Racing sports enthusiasts know they need to stay hydrated, but what does that mean, and what happens if they don’t?

This article delves into what happens internally and externally when we are dehydrated.

Plus, it looks at the best ways to detect dehydration and, most importantly, how to stay hydrated, so you don’t have to worry about dehydration in the first place.

What is dehydration?

Dehydration occurs when our bodies lose vital electrolytes through sweating, essentially the body’s built-in cooling mechanism.

The American Chemical Society describes electrolytes as salts ingested primarily through food that dissolve into positive or negative charges.

And in the field of sports performance, the most important electrolytes are potassium, sodium, calcium, and magnesium.

So why are electrolytes so essential to runners? Electrolytes control the movement of water in your body’s cells and nerve impulses in your body.


These salts play a crucial role in brain function, muscle firing, and even your heartbeat.

During a training session, the following situations occur when these electrolytes are lost:

  • Muscle fatigue sets in earlier.
  • The heart rate increases.
  • Performance decreases.
  • Mental clarity suffers.

Additionally, dehydration affects recovery long after your run or training session. Because it prevents your muscles from recovering, dehydration during a single workout can hamper your activities for days afterward.

Performance may continue to suffer since your muscles will not have fully recovered.

Signs of dehydration for runners

The best-known indicator of dehydration is thirst. As a general rule of thumb, you’re likely already dehydrated if you’re thirsty. Dry mouth, dry eyes, and even dry skin can also serve as signs. Be on the lookout for headaches and nausea!

Other lesser-known signs include:

  • Mental fatigue.
  • Lack of motivation.
  • Increased heart rate to an average running pace.

Also, excessive sweating and low sweating can indicate dehydration. Excess sweating is your body’s way of warning you that you are wasting energy and losing electrolytes that need to be replaced.

A light sweat is a bit more complicated than a sign. The absence of sweating under conditions where you would typically sweat, also known as hypohidrosis, often indicates heat exhaustion, partially or caused by dehydration.

Heat exhaustion refers to any mild heat-related illness. Nausea, vomiting, and weakness are all symptoms of heat exhaustion when the body does not cool down through sweating.

Extreme heat exhaustion is called heatstroke and indicates the total failure of your body to regulate its temperature.

Symptoms of heatstroke include:

  • High fever.
  • Fast heart rate
  • Loss of consciousness

While dehydration is not always the cause of excessive sweating, it is likely a factor if you sweat little during a training session.

Because of this, be sure to take note of your sweat levels mid-workout. Hydrate often to replenish electrolytes if you’re sweating too much, and find a way to externally cool your body temperature if you’re sweating too much.

Dehydration looks different in everyone, so you probably won’t have all of the symptoms listed above, even if you are dehydrated. As a result, it is essential to know your own body and find out what your body’s response is to the loss of those vital electrolytes.

Hydration Tips for Runners: How to Avoid Dehydration

Daily hydration is the easiest way to avoid all of the above symptoms and signs.

Experts recommend drinking 8-10 glasses of water every day while also incorporating foods high in water content into your diet.

The following foods are great options to help you stay hydrated:

  • Cucumbers
  • Watermelons
  • Spinach.
  • Lettuce.
  • Cauliflower.
  • Broccoli.
  • Radishes
  • Tomatoes.
  • Green peppers.

Also, you need to find a good hydration product that you can use before, during, and after your training sessions to replenish the electrolytes that your body loses.

A hydration product provides vital electrolytes (sodium, potassium, calcium, and magnesium) and crucial minerals, generally lost through sweating during a run or workout.

Sports drinks are the most common hydration products; however, many of them can be extremely high in sugar, which can have other adverse effects on your body.

When choosing a hydration drink, look for a product with between 250 and 350 grams of sodium and less than 10 grams of sugar. Make sure to hydrate with this every 20 minutes or so while training and before and after the session.

SOS is an ideal product because it is medically formulated to be similar to an IV hydration supplement that a patient would receive in a hospital. It also tastes good and is high in sodium but low in sugar.

It can take up to 48 hours to recover from dehydration, but you can avoid it by simply drinking enough fluids throughout the day and making sure to hydrate with a high-quality product while you train.

Hydration Tips for Runners: Preparing for Race Day

Remember to hydrate during your workouts and drink water throughout the day step in the right direction for a hydrated run.

However, you should use all of your training sessions as hydration tests for race day.

If hydrating every 20 minutes in the long run left you with a headache or other dehydration symptoms, that’s a good sign that you may need to increase your efforts and try to hydrate every 10-15 minutes in your next training session.

Get an in-depth assessment of how your hydration program works after every workout to know precisely what your body needs during your big run.

Also, check the heading and the weather forecast before a race. Dehydration is one of the worst surprises of race day, but doing a little preparation ahead of time can help you avoid dehydration altogether.

Viewing the tour ahead of time can tell you how many assist stations there will be so you can pack your hydration products.

Also, if you know the race will be hilly and hot, mainly in the sun or upwind, you can try training in those conditions to understand what it takes to keep your body hydrated and achieve optimal performance.

Final thoughts

As you can see, staying hydrated as a runner just knows your own body. Monitor your symptoms and use trial and error to see what works.

To keep your body hydrated regularly, drink water throughout the day and take a well-formulated hydration supplement to replenish electrolytes lost during your workout, and you should be good to go.