Much of our planet’s surface is made up of water; it makes up our oceans, rivers, the great expanses of ice in North and South Polar Regions, and it also makes up most of us.
For humans, water is the essential medium we require for our physiological systems to function well. In this aquatic medium important metabolic processes occur. Its presence ensures the shape of the individual cells that make up our tissues is maintained, that our blood can flow and that our endocrine (hormonal) and immune systems function well.
It is also a medium by which we lose heat to the environment in evaporating sweat, and how we get rid of waste products excreted in urine.
So for humans the problem is that it must therefore be replaced constantly. Without adequate hydration our physiology at all levels (cells, organs, systems) will be placed under strain and we will struggle. Most of us will cope with this over short periods but being hypo-hydrated (under-hydrated) may be a factor in ill health should this be allowed to continue.
However, even when armed with this knowledge the advice on what to drink can be confusing; how much should we drink and when, is it enough or too much?
The internet is awash with pages of information. For example; a recent search on Google with the string “hydration advice” revealed 664,000 hits!
With our bodies being made up of almost two thirds water we must be constantly replenishing this with fluids that we drink and foods that we consume (did you know, depending on your diet up to 20% of your fluid requirements comes in the form of the foods you eat). With this in mind what should we be drinking and how much?
This last question depends on many factors such as a person’s age, the weather and any activity undertaken. If its hot or you are sweating from exercise obviously you’ll need to replace more. However there are some good “Rules of Thumb” from European recommendations.
Women need about 1.6L per day and men about 2L in addition to fluid each of us get from our diet.
Does it really matter what we drink or can we make better choices? Water is clearly the choice most of us would go for; it can replenish the fluids lost without adding calories. However, other choices include fruit and vegetable juices and smoothies. The advantages here are that they will contain some of the other micronutrients we require in the form of vitamins, minerals and depending on what you put in them various other plant substances from the fruit or vegetable.
The downside is that they contain calories and if made with fruit much of this can be sugar related. They may also be fairly acidic and this acidity along with the hidden sugars potentially affect the health of your teeth. Our advice; drink water for your hydration and treat yourself to orange juice or similar whilst being very aware of any added sugars - if you can't juice your own fresh fruit, always read the label!
What about if we exercise, do we need to drink to a regime in anticipation of becoming dehydrated, or should we be drinking to thirst, in other words allowing ad libitum intake? Are there any issues with fluid related physiological stress?
Well the simple answer is yes. Without going into a long in depth scientific review (that has already been done by Cotter et al). The simple fact is that physiological, central nervous system and ultimately overall physical function can be acutely impaired by either drinking too little or by drinking too much in the acute setting.
Very often it is either lack of availability of both water (and salt) or behaviours that are inappropriate (like an obsession with drinking lots of water during exercise) that are problematic. Somehow we must get the balance right particularly so that over longer periods a state of chronic dehydration which has been implicated in the development of kidney stones and kidney disease is avoided.
There is evidence to show that being mildly dehydrated can alter perceptions of tiredness and fatigue, but this is in controlled work whereas under normal free living situations, the body’s stimulation of the very powerful driver thirst would be enough to mitigate against this.
Hydration is a subject that has experienced much argument and debate in the scientific communities around the world, especially when exercise is involved and a massive industry has risen up around it.
What do we advocate at The Strength Temple?
Firstly, under most scenarios of life where access to water is easy, drinking when thirsty is probably preferable. In fact the old Zen maxim “Eat when hungry and drink when thirsty” would see us well in most of what we do. But this does mean that you need to have your drink with you so you can consume it when you need it. Therefore get into a habit of having a bottle with you.
Bottles that are BPA free are preferable. This means that contaminants from the plastic aren’t going to leach into the fluid in your bottle and therefore end up in your system. I personally use bottles by the US manufacturer Nalgene, because they are virtually indestructible and perfect for chucking in my kit bag, in my rucksack and I even have one for the office and one for the car. Once you have one you can kept it topped up and take it with you everywhere. You can buy them from Amazon and we've included a link via the picture here if you'd like to order some.
The second thing to do is to decide what it is you want to drink. Water is preferable to something stuffed full of sugar and artificial flavourings, acidifiers, sweeteners, preservatives and stuff that makes it fizzy. When in nature or evolution did we adapt to consume this stuff? We haven’t, and therefore we are probably better off without it. That is not to say you can’t have these things on occasion. Just don’t have them all of the time!
What about whether it is tap or bottled water, or something that has been filtered? Well I guess that depends on whereabouts you live in the world and the quality of the water that is delivered to your tap. It probably isn’t harmful to drink tap water in most western countries but it probably could be improved. Certainly filtering tap water or using RO systems will remove many salt and other impurities but you could end up in a situation where you have to add minerals back into your water.
If you take me for example, I live in an area where the tap water is exceptionally hard. Therefore, as a family we use a filter before using water to drink, make up other drinks or to go in the kettle to make our tea.
Water can come from different sources, each with their own qualities. For example: water that is collected from rain may taste very different from water from a well. The difference can be the minerals dissolved in the well water or pollutants collected from air as it falls through the air. River and stream water collects specific qualities depending on its journey, if water falls from height or passes through rapids it may become enlivened, but it can also pick up impurities on its journey.
Water from lakes and big rivers will pick up impurities from farming and manufacturing processes. Water is cleaned and often recycled it contains bacteria and chemicals. Modern processing cleans the water but to what degree is debatable (and of course this depends where in the world you are too). Modern treatment works add other agents to act as disinfectants. The most widely used is chlorine which is pretty effective and in some parts of the world sodium fluoride is also added for dental decay prevention. Mostly this makes water safe for human consumption, but I suspect it could be made better and taste nicer, this is where my house hold jug water filter comes in.
I can taste the difference and not only that I can see it too, there is less of a visible layer on top of my tea made with filtered water compared to when I make it without. I got into a habit of topping up my BPA free bottle and taking it with me when I go out the door for work in the morning. It sits on my desk beside my PC acting both as a reminder to drink and also so it is readily available to drink the moment I feel thirsty.
Get a bottle and make hydration part of your healthy body maintenance routine, and don't forget to.......
Dr Dan Roiz de Sa