Humans are around 60% water and some organs, like the brain and heart, are made up of over 70% water. All our cells, organs, and tissues therefore require a good, consistent supply of water to perform important bodily functions.
It’s safe to say we have an uncanny affinity with H2O. So much so that a 1% dip in hydration will trigger sensations of thirst. But what about when we're exercising – how important is it to stay hydrated then?
As experts in all things hydration, we’re here to make the science simple, so you can perform at your best in your next athletic endeavour!
Why is hydration important in sport?
Water isn’t only needed for essential physiological processes like breathing and digesting food, it’s also key to optimising and improving your physical performance, particularly during periods of intense exertion like when playing sports or during high-intensity interval training (HIIT).
Indeed, hydration is central to performance – and no matter the sport, proper hydration will set you up for success, both mentally and physically, while also helping to prevent injury.
That's why we believe in the power of good hydration practices; it's the easiest way to give you an edge on competition and improve performance. Plus, it’s great for your overall wellbeing!
Science made simple: the benefits of hydration in sport
In short, water is the single best 'supplement' you can take and its benefits are manifold. Here are four key ways water can benefit you while playing sports:
1. Temperature regulation
Staying adequately hydrated helps control the body’s temperature via thermoregulation. In more simple terms, when athletes exercise, they sweat, and when sweat evaporates, it removes heat from the skin’s surface and lowers the body’s core temperature.
Maintaining temperature is essential to prevent heat-related illness. While this might sound scary, it’s easy to remediate by drinking enough fluid throughout the day and replacing fluid lost during a workout.
Without proper fluid replacement, you can start to experience symptoms of dehydration: dry mouth, feeling dizzy, and fatigue, to name a few.
2. Blood circulation
A good balance of body fluids is also essential for blood circulation – our body's delivery system. When blood is pumped around the body, it carries nutrients and oxygen to our muscles and picks up metabolic waste (lactic acid) before transporting it to the liver for removal.
Better circulation, then, can help reduce overall feelings of fatigue and cardiovascular strain both during and after a workout.
3. Cognitive function
Another factor that highlights the importance of hydration is the effect it has on cognitive function and mental ability. Indeed, research shows good hydration leads to better decision-making and helps sustain concentration for longer periods, both of which are essential for sports requiring quick thinking, dexterity, and teamwork.
4. Muscle function
When our muscles are hydrated, they work more efficiently and are less prone to tears, strains, and muscle cramps. This is because water keeps muscles pliable, flexible, and strong – all key factors for functions like relaxation, contraction, and stretching.
How does dehydration affect sports performance?
When we aren't properly hydrated, we can become dehydrated. Dehydration occurs when the body loses more fluid than it takes in. This is a problem since, as we've covered, water is essential for all kinds of physiological functions.
Because we’re reliant on water, we’re incredibly sensitive to acute changes in hydration levels. Just a 2% drop in body mass (weight) through fluid loss during exercise or physical activity is enough to negatively affect physical and mental performance. As such, the importance of being hydrated can't be overstated.
Negative effects of dehydration include:
Increased core body temperature
Increased muscle fatigue
Increased use of stored glycogen
Less transport of blood oxygen
Reduced concentration
Lower mental and physical performance
According to the NHS guidelines, we should be drinking around 2 litres of water every day to maintain a healthy fluid balance and achieve optimal hydration. Yet research shows 70% of people often go seven or more hours without drinking any – and that's not even factoring in a strenuous exercise session!
For those looking to improve athletic performance, then, staying hydrated is essential. Drinking water is the simplest way to prevent dehydration, so always monitor your fluid intake and drink plenty of water throughout the day – before, during, and after exercise.
How much fluid should you consume before exercise?
You should be well-hydrated before exercising to reduce the negative effects of fluid loss during and after physical activity. You can check three bodily metrics to assess whether you're dehydrated:
Weight. If you're physically active, your body weight should stay consistent, so a body mass decrease of more than 1% could be the result of dehydration, especially first thing in the morning.
Urine. When you're dehydrated, urine becomes darker and more concentrated, meaning you can use the colour of your urine to determine your hydration levels – the lighter, the better.
Thirst. A 1% drop in hydration will trigger the bodily sensation of thirst, so if you're thirsty then chances are you could be dehydrated.
If you think you could be dehydrated, drink around 500 ml of water with an additional 200-300 mg of electrolytes.
We'd recommend avoiding most sports drinks and energy drinks since these can be high in sugar and calories. Instead, a cold glass of filtered water with some Himalayan pink salt for electrolytes can help kickstart the rehydration process before your workout.
Alternatively, caffeinated drinks like tea and coffee can also help with hydration and encourage peak performance by reducing your perceived exertion. For ultimate convenience, choose HydroTap – the world's most advanced drinking water system. Pouring both filtered chilled and boiling water with the touch of a button, it's never been easier to get hydrated and get active!
Should I drink water during exercise?
Depending on your body size and weight, the type of exercise you're doing, and how long you're doing it for, the amount of water you should consume during exercise will vary.
There are many different calculations you can do, like working out your sweat loss during exercise. But these are often overkill unless you're a professional athlete.
If you're getting in a quick HIIT session at home or are off out on a 5K run, then it's unlikely you'll need to rehydrate on the go; however, for workouts lasting more than an hour, it's important to replace lost fluids and maintain hydration.
As a general rule, consume around 500ml of water for every hour of exercise for optimal performance.
Why is it important to rehydrate after exercise?
During high-intensity exercise, you can lose up to 10% of your total body weight from sweating alone. In fact, you continue to lose fluids through sweat and urine for some time afterwards as the body attempts to bring down its core temperature.
Therefore, to avoid severe dehydration, it's important to increase your fluid intake after exercise. Again, there are numerous equations you can do here, but the standard advice is a few sips of water, little and often, until you cool down and begin to feel more hydrated.
As a rule, you're looking to replace the fluid you lost, so the more you sweat during your workout, the more water you will need to rehydrate.
You can learn more about dehydration, the benefits of staying hydrated, and our top hydration tips in our easy-to-understand hydration guide.