Give or take, our bodies are comprised of around 65-70% water. That’s quite a lot really. Particularly if you think about your body as being a pint glass where 70% is water and only 30% is made up of other bits and pieces, like limbs and stuff... Our brain is higher than 70% and our lungs are higher still. Interesting thought, right?
Did you know: the more body fat we have, the less water is in our body, pound for pound? Body fat is anhydrous (has very little stored water) whereas muscle can be as high as 70% water!
Rather than just provide a few tips on how to drink more water, our goal here is to try to educate and get us all thinking about what we’re putting into their remarkable bodies. Remember - to create lasting habits and new changes in our lives, knowing WHY we are doing something really helps make it stick.
Now then. We are told that we must drink two litres of water each day. But that’s like saying, “you’re going outside so you must wear a warm winter coat, fur-lined and all”... even though you live in Brazil and it’s the middle of summer. The statement, completely reasonable in some cases, doesn’t account for any variation of circumstance although it is still a good baseline if your daily H20 intake is generally less than this amount. However, because we are all infinitely unique and have differing amounts of muscle and fat, two litres of fluid daily won’t even come close to the needs of some of us. Side note: if you are planning to stroll along Copacabana Beach today, feel free to don the coat if you wish!
So. Water. Other than fall on our heads too often in the UK, what does it do for us physiologically, that means we really should be paying more attention to how much we consume?
a) Critical bodily processes such as digestion, circulation and excretion cannot occur without it.
b) Water acts as a building material for growth and repair of the body.
c) It serves as a transport vehicle for digestion and the transportation of nutrients to the cells within the blood. Maintaining blood volume enhances nutrient delivery and makes us feel healthy and well.
d) Mechanical functions - water lubricates joints such as the synovial fluid in the knees. Water also provides the fluid in tears where their function is to clear out or remove any debris or dirt in the eyes (and sob at the occasional rom-com).
e) It is a great medium for holding and getting rid of heat.
f) Finally, water aids metabolism so it is a vital part of your ability to burn fat.
Fine. So we can see that water is to our bodies as popcorn is to the cinema...a complete necessity. Actually, since we’re all about superfoods and healthier living, let’s rephrase that to - water is to our bodies as peas are to carrots!
Even so, what does that mean in a practical sense? What happens if we don’t drink enough? How do we know how much and when to drink?
Staying hydrated when exercising with respect to burning calories
How should we measure our hydration level during physical activity? We need to weigh ourselves! Scales can only tell you what you weigh (even though we rarely believe them anyway), they won’t you how much body fat or muscle you have. If we go running or to a spin class and lose 10 lbs, it is impossible for us to have lost 10 lbs of body fat; the energy equation simply won’t allow it.
Note: we need to burn around 3500 calories to lose just 1 pound of body fat (1 lbs = 0.45 kg). Therefore to lose 1 pound of body fat (or 0.45 kg) at 100 calories per mile, you would have to walk 35 miles.
So what is happening here? Fluid loss!
Generally, the average adult will eliminate around 2.5 litres of water each day. Around 1.5 litres comes through urine and the rest is from sweat, breathing and bowel movements. Depending on your level of physical activity, the amount eliminated through sweat could be significantly different between individuals. Doing anything aerobic increases your rate of breathing so the amount of fluid you lose through breathing is obviously greater when you exercise - unless, of course, your athletic ability is akin to T-1000 from Terminator! Because our breath is 100% humidified (has lots of water in it), more breathing means more body water lost.
If each 0.45 kg of weight lost during exercise is actually 0.45 kg of fluid, that’s very significant and should not be overlooked! To fully rehydrate, you would need between 450g and 650g of fluid. Why can’t we just replace 450g of sweat with 450g of water? Because some of that water is lost in urine and breathing and what we are trying to do is rehydrate the muscle, not just replace sweat. If you lose 2 kg during vigorous exercise, we are actually losing almost 2 kg of fluid, not fat! Consider this to our recommended intake of 2 litres per day...where 2 kg of water = 2 litres of water.
Interesting fact: as little as a 1-2% decrease in body weight can affect your athletic or aerobic performance by around 15-20%. Often we look to the complex and overlook the simple solution to increase our performance edge. Always keep in mind the value of hydration and, where possible, remember to weigh yourself before and after exercise to calculate body weight loss.
Isotonic sports drinks, water or both?
If you exercise for less than an hour at moderate intensity, water is absolutely fine and would usually be preferable to anything else. If your level of exercise is more intense or if you are in a hot climate/room for more than 30 minutes, you should probably have a sports drink in addition to water.
Sports drinks such as lucozade and powerade are intended to be used during and after physical activity because they re-stock our electrolyte levels. In this case, the important electrolyte is sodium which is lost when we sweat. Some people believe that potassium is the major electrolyte lost but this is insignificant when compared with sodium.
Do you get cramp when exercising? Contrary to popular belief of having too much sodium, what’s causing the cramp is often the loss of sodium in your sweat - or another mineral deficiency such as magnesium or potassium. Solution: bananas! They are are great for energy but also for potassium replenishment. However, don’t forget to replace the sodium as well. Out of the two choices, a sports drink would be advantageous because it not only provides more fluid but also replaces the sodium that has been lost - check out the sodium content on the labels of drinks like powerade and lucozade!
Hydration from foods
Think of food as fluid! Well, some foods anyway... high water volume foods such as fruits and vegetables are 80-90% water. For people who struggle with hydration because they cannot drink more involuntary fluid than they already do, food becomes the key to optimal hydration. In addition to fruits and vegetables, other high water volume foods can be milk, yoghurt and soup.
How heat and humidity can affect fluid balance
Many factors influence fluid balance and one of the main factors is the heat and humidity of our environment. In order to cool you, sweat needs to dry off of your skin. However, sweat doesn’t evaporate when the humidity is high so the body’s natural response is to produce more sweat... Somewhat annoying and a bit of a vicious circle; especially if you’re trying your best to avoid those dreaded sweat patches on your morning walk to the train station which often turns into a manic sprint! In this instance, your body does not sense that the sweat being produced is not cooling you effectively so it will produce more and more sweat.
In a colder environment the humidity is relatively low which can be dehydrating to the body and your skin, mouth and lips may dry out. Although cold temperatures can be dehydrating, you don’t have the environmental triggers to tell you. You may not feel sweat on your skin but that doesn’t mean you aren’t losing moisture in another way.
Do you travel on airplanes regularly or perhaps you noticed feeling a tad dehydrated on your return trip back from the Costa del Sol? That could be the excess alcohol but it may also be due to fluid loss from the lack of humidity in the airplane cabin. Your breath is humidified at 100% and in a pressurised cabin the humidity will typically be 0-20%. You are not sweating or exercising but just the act of breathing can drastically increase the amount of fluid loss in this environment without you realising it. So, in addition to remembering to share your arm rest (yeah right!), drink plenty of water as well!
Signs of dehydration
Unfortunately, your level of thirst is a poor measure of hydration because there is a lag between the time you get dehydrated and the time you experience thirst. Not only that, the older we get, the less sensitive our thirst mechanism is so we need to be mindful that just because we aren’t thirsty, it doesn’t mean that our bodies don’t need fluid. Certain pain medications can also blunt our sensation of thirst.
a) Having a dry mouth is the last outward sign of dehydration.
b) A severely dehydrated body generally produces orange or dark coloured urine. Urine that is yellow means the body is partially dehydrated and clear urine typically means that the body is carefully hydrated.
c) If you are thirsty, your cells are already dehydrated.
d) Some side effects may include increased levels of stress, headaches, back pain, allergies or high blood pressure.
e) Even mild dehydration can cause decreased coordination, fatigue and impairment of judgement.
Should we drink water before, during or after meals?
Generally, it is advisable to drink water before and after your meals, not during. Drinking prior to eating will help to fill you up and stop you overeating as well as aiding your body to properly digest your food. Similarly, refraining from drinking while you eat gives you the chance to breathe correctly which also helps with the digestion of your food.
Too much of a good thing
It’s fair to say that aside from oxygen, water is the single most important element to our health but we must also consider the other side of the coin! Firstly, drinking too much can dilute the amount of sodium in your blood. As we now know, sodium and potassium are essential electrolytes that your body works hard to keep in balance.
Hyponatremia is an electrolyte abnormality due to low sodium levels from overhydration. It can cause the brain to swell and is characterised by lethargy and confusion, muscle twitching, and seizures. In extreme circumstances it can result in coma and death can occur. If you are a marathon runner and weigh 140 lbs before the race but 143 lbs after then you drank approximately 3 lbs more in fluid than you lost in sweat. Because the symptoms are similar, feeling lightheaded or confused at the end of a long and grueling race might be confused with dehydration. Therefore, to help prevent hyponatremia, be conscious of your sweat rate and weigh yourself before and after any kind of extended exercise like a marathon or long-distance bike ride to be on the safe side.
Alcohol, caffeine and a final thought
We hope that it’s reasonable to say that being properly hydrated is about far more than drinking water only when we feel thirsty. If you’re reading this while sipping a cup of tea, coffee or a glass of wine, enjoy it! But it’s also worth mentioning that caffeine and alcohol can have dehydrating effects; alcohol stimulates your body to produce more urine and the caffeine found in tea, coffee and energy drinks is a diuretic. However if you’re used to drinking tea or coffee then it is likely that you have acclimated to that level of caffeine and won’t lose a significant amount of fluid. Regardless, any of these drinks (in moderation) are preferable to drinking no fluid at all and will help give your body the best chance of working the way it should!
So, the next time you walk past the water cooler on your way to the office canteen or get asked ‘what drink would you like with that?’ at McDonald's, we're hopeful that you will at least consider your hydration state instead of the usual large cappuccino with extra choccy sprinkles!
Tip: if you want to spruce up your water while adding some valuable nutrients at the same time, try chopping up some lemons and limes (or otherwise choice pieces of fruit) and place within a fruit infuser water bottle. If you don’t have one of these, a water bottle with a wide rim will do just fine.