Hydration, and why it's important

Hydration, and why it's important

Go without food and you can survive for weeks, but we all know that you can only survive a few days without water.  On average, the human body is 60 percent water and it plays a critical role in every bodily function. You can lose a litre or two of fluid an hour through exercise through sweating and breathing.

As much as staying hydrated is important for survival, it can play a vital role in our body composition yet up to 40 percent of recreational gym goers are partially dehydrated during their workouts. 

Functions of water in the body during exercise

Water plays a key role in the following:

  • creating the energy necessary to fuel each cell through the Krebs cycle in the intracellular water.

  • regulating body temperature via sweating

  • transporting carbs and proteins in the body through water in the blood stream

  • a key component in the synovial fluid that lubricates your joints and the cerebrospinal fluid which acts as a shock absorber for the brain and spine

What influences hydration?

Activity levels – the duration and intensity level of your sessions dramatically impact your fluid requirements.  In addition, the more muscle groups you’re activating, the more energy your body requires and the more water you’ll need.

Temperature and climate - hot and humid environments can increase rates of water loss through sweating. Evaporation rates in humid conditions are reduced, hence sweat cannot cool you as quickly as it normally would do.  A higher body temperature results and more fluids are required.

Altitude – at higher altitudes, the lower air pressure and low humidity means that evaporation of sweat from your skin accelerates.  You probably won’t notice but you’re still losing fluids.  Higher altitudes also increase urination rates as the body attempts to control blood pH.

Hydration and gaining muscle.

Studies have shown that when cells lose water and cell volume, protein production decreases and catabolism increases.  Concurrently, when just 3% dehydrated, exercise performance can be impacted, this is particularly felt during anaerobic exercise such as lifting in the gym, or sprinting. 

This research demonstrated that blood flow to the exercising muscles declines significantly during longer sessions when dehydrated.  Finally, another study showed that dehydration to as little as 1.5% of body mass decreased the one max rep bench press in ten weight-trained males.  

If you’re even slightly dehydrated, you can’t train as long or hard in the gym which will undoubtedly impact your gains over time

Hydration and fat loss

Researchers have found that people who are obese are more likely to be dehydrated, and vice versa, concluding that clinicians should consider hydration as a key component of a fat loss diet.  

Other studies show that increasing water intake can result in greater fat loss than diet alone, with water drinkers in a group of obese adults losing 44% more weight than the reduced calorie diet by simply adding 500ml of water prior to each meal. 

How can I tell if I’m dehydrated?

Now that we understand how important it is, what do we need to look out for other than just feeling thirsty if we’re to avoid running low on fluids?  Here’s a list of telltale signs to keep an eye on:

  • Low energy

  • Darker colored urine (medium to dark yellow)

  • Lack of urine

  • Irritability

  • Headaches

  • Confusion and inability to concentrate

  • Dizziness

  • Muscle cramp

  • Faster heartbeat

  • Nausea

How much do I need to drink?

Elite athletes monitor their body weight and use this to calculate their sweat rate, determining how much hydration they need. That’s pretty unnecessary for us mere mortals.  There are no exact rules for how much water to drink while exercising, because everyone is different.  A good place to start is to make sure you drink 500 ml of water a couple of hours before you plan to exercise, then about half that whilst you warm up.  If you try this and sip water as you train and still find yourself getting thirsty during your session then you’re about 2 percent dehydrated and you will need more than this.

Unless it’s super-hot and humid, or you’re training for longer than 60-90, minutes, regular water will do the trick.  If you’re going hard for longer then electrolytes in a sports drink will be necessary to keep you going.

For most of us, remembering to drink water before exercising and carrying a water bottle so you can drink when you’re thirsty is all you need to do to stay hydrated, and ready to blast a workout.

Hydration – so what?

Anyone, from lifters to runners, can become dehydrated if fluid loss is greater than fluid intake. 

Your hydration status is just as important as getting enough sleep or good quality food for muscle growth and improved physical performance. Meeting your daily hydration needs could be the difference between accomplishing your desired body composition goals and screwing them up. 

In summary, dehydration could potentially lead to slowed muscle growth, possible muscle mass catabolism, increased risk of injury, and impaired gym efforts.  If that doesn’t have you reaching for the gym water bottle then nothing will.

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