Hydration is crucial for racing drivers, as it impacts physical performance and cognitive function on the track. With the multiple layers of protective clothing, drivers can experience extreme heat during races, leading to significant fluid loss through sweat. Sweat causes dehydration, which can impair concentration, slow reaction times, and increase the risk of making mistakes - all critical for driving performance.

Without proper fluid replacement, losses in body weight may exceed 3% of body weight throughout a race, potentially negatively impacting driving ability. Overhydration, on the other hand, can be equally dangerous, causing hyponatremia.

In this edition of the Margins Newsletter, I will share an article written by ****Carlson, Lara A, Lawrence, Michael A, and Kenefick, Robert W, titled ‘Hydration Status and Thermoregulatory Responses in Drivers During Competitive Racing’. This outlines the impact of hydration on the performance of Racing Drivers. I will provide evidence-based strategies to maintain proper hydration and avoid the risks associated with dehydration or overhydration.

What is Dehydration?

Dehydration occurs when the body loses more fluid than it takes in, resulting in insufficient water and other fluids to carry out normal bodily functions. Our bodies are roughly 60% water, and there’s a reason for that. Every system in our body (cardiovascular, muscular, etc.) needs this water to function. Losing water stops the body’s systems from working at their best.

In Motorsports, dehydration can be a significant concern for racing drivers due to exposure to high temperatures and protective clothing. During competitive stock car racing, drivers experience substantial fluid losses through sweating, the primary cooling method in hot environments. A study on NASCAR drivers found that they can lose an average of 0.77% of their body weight during a race, with sweat rates averaging 0.63 L/h.

It’s simple, less water in your body leads to lower physical and cognitive performance. But how much water is enough?

How much Water should Racing Drivers drink?

The amount of water a racing driver needs varies based on factors such as race duration, environmental conditions, and individual sweat rates. While drivers may not be the same as other high-intensity sports (running, basketball, etc.), the intense heat inside the car (which can exceed 50°C), combined with the stressors of Motorsport, leads to significant fluid loss.

Studies suggest that drivers can lose up to 3 litres of sweat in a single race. A general guideline is to consume 200-300 ml of water 30 minutes before driving and to hydrate consistently during long stints, using hydration systems where possible. However, for drivers at the start of their careers, this may not be possible (I’ll cover an alternative later).

The easiest method to gauge your hydration is to look down when you visit the toilet. The colour of your urine can be a good indicator of your hydration levels, regardless of your feelings of thirst. Clear or light yellow urine indicates proper hydration, while darker urine suggests dehydration.

Electrolytes boost Hydration

Just like in running, maintaining electrolyte balance is key for drivers. The loss of sodium, potassium, and other electrolytes through sweat can lead to cramps, dizziness, and slower reflexes. Research shows that maintaining electrolyte levels can improve endurance and reduce the mental fatigue caused by heat stress.

Drivers should incorporate electrolytes into their hydration plan, especially during long races or in hot conditions. For shorter stints, water may suffice. However, for endurance races or hot weather, consider using electrolyte drinks to maintain fluid balance. After a race, replenish both fluids and electrolytes as quickly as possible. Coconut water, sports drinks, or electrolyte tablets (not champagne) can speed up recovery and reduce muscle soreness.

How to Stay Hydrated in Racing

To address these challenges, motorsport athletes and teams should consider implementing effective fluid replacement plans before, during, and after races.

It's crucial to start the race well-hydrated and consume fluids regularly throughout the event. Additionally, improving cardiovascular fitness and heat acclimatisation can help drivers better tolerate the thermal stress of racing.

To help stay hydrated on race day, here are a few strategies:

• Start your day with a glass of water to give you a head start on hydration.

• Set hydration reminders to drink at intervals throughout the day.

• Drink small, frequent amounts of water instead of large gulps, which can lead to discomfort during long stints. If you have the facilities, do this during the race every 10-15 laps or so.

• Refuel yourself immediately after the race.

Hydration for Racing Drivers without a drinks system

As a kart driver, I don’t have a drinks system during races. I counter this with consistently drinking water, electrolytes and carbohydrates (in the form of energy gels) throughout the day in the lead-up to the race. Although it is still not the ideal scenario (I compete in endurance races), it is better than nothing.

The first thing I do when I finish the race is consume fluids and carbohydrates to replenish the energy and water I had spent during the session.

Avoiding Overhydration in Motorsports

The solution to dehydration isn’t to drink excessive amounts of water, though.

Overhydration without replacing electrolytes can lead to hyponatremia, a condition where sodium levels drop too low. This can cause headaches, nausea, and confusion, which can be detrimental to driver safety. In severe cases, it can lead to seizures and even death. Drivers, especially those in endurance events, must be cautious not to drink excessive water without sodium intake.

To avoid overhydration:

• Listen to your body’s natural cues instead of strictly following hydration schedules.

• Electrolyte solutions or sodium tablets help maintain the balance between water intake and electrolyte levels during extended race sessions.

Final Thoughts

It’s often not easy to know you’re dehydrated until it’s too late. To avoid this and maintain your cognitive and physical performance, build the habit of hydration. Drink water regularly, and add electrolytes before, during and after exercise.