I define hydration as maintaining adequate fluid and electrolytes in the body. So broadly speaking we have two key components to hydration, water and salts. The human body is made up of a lot of water, and adequate water intake is important for maintaining fluid levels inside the cells, as well as keeping our blood thin and easy to move around our body. Electrolytes are tricker so lets go into this in a bit more detail. My experience of electrolytes growing up was having a blue powerade at sport to prevent cramp (or helping with a hangover), and for a lot of people that’s about as far as we get with our understanding.
What are electrolytes? Essentially, they are salt ions, the main ones being sodium, potassium, magnesium, calcium, chloride, phosphate and bicarbonate. These have a multitude of functions in the body, mainly related to producing electrical transmissions in our nervous system (hence the name electro-lytes). Every single message that is sent through our nervous system (aka nerve impulses) involve electrical transmission caused by these salt ions crossing channels in our cell walls. We need electrolytes in order for any of these messages to fire, so that means for every thought and every muscle contraction (including our heart and diaphragm). They also help us with maintaining fluid balance, help with energy production, help with hormonal balance and keep our bones strong.
To understand good hydration I think it’s best to start with understanding dehydration, which is essentially a lack of fluid and electrolytes in the body. This is generally caused by either an increase in the amount of fluid/electrolytes leaving the body, or by a decrease in the amount of fluid/electrolytes entering the body. This can cause symptom such as:
- Dry skin/lips
- Dark urine
- Headaches
- Mood disruptions
- Memory issues
- Muscle cramps and tightness
- Fatigue and brain fog
- Constipation
- Decreased blood pressure and dizziness/fainting
- Nausea
- Rapid heart beat
- Trouble sleeping
- Increased urination at night time
Some of these symptoms are obvious to us, others can be a bit more subtle. In my own experience I didn’t realise I was dehydrated until I wasn’t. Once I started hydrating properly using electrolytes, my energy increased, my brain fog and fatigue decreased dramatically, some chronic muscle tightness in my back went away and my sleep improved.
Why do we get dehydrated? This is a big rabbit hole that we can go down, but for the purpose of today’s blog we’ll keep in as an overview and dive into the pieces deeper in the future. Some common causes of dehydration are:
- Physical activity. This can impact the amount of electrolytes leaving the body via increases in breath rates and sweating. In a litre of sweat we can lose up to 2000mg sodium, 500mg potassium, 3000mg chloride, 100mg calcium and 100mg magnesium.
- Dietary deficiencies. I am a massive fan of whole foods-based eating. However, these foods generally contain a heap less sodium than their heavily processed alternatives. Which means we have to add that salt back in somewhere. This is amplified if we eat a low carb/ketogenic diet as when insulin is low, our kidneys excrete extra sodium, often leading to the dreaded ‘keto flu’. I have always felt best on a fairly low carb diet, which means I might need more salt than most.
- Another factor in this is the recommended daily allowances for salt that have guided our eating for decades. Generally, the government recommended daily allowances of sodium are less than 2g per day, which is probably sound advice if you have certain heart issues and other co-morbidities, as it can help to lower your blood pressure. However, the problem lies when these guidelines are pushed onto the general public by media stories and health professionals, meaning most people will try to decrease the amount of salt they add to food etc, often leading to deficiencies in the general population
- This does two things, one is it increases our bladder contractility, meaning we get the urge to pee more. Also it makes our urine more salty, a cup of coffee can cause us to excrete up to 400mg of extra sodium. I love my morning coffee(s) and I’m not suggesting that you give it up, just balance it by using more electrolytes alongside it.
- Pregnancy/breastfeeding. This is a whole topic on it’s own and doesn’t have a heap of research around it yet. However, if you’re either growing another small human or feeding one, you need a lot more salt
So what does good hydration look like? Again it comes back to the two key components, water and electrolytes, and will change depending on the person. As a starting point I am a big fan of Andy Galpin’s equation for working out how much fluid to drink per day. He states that we should aim to drink half an ounce of water, per pound of body weight per day. So in metric terms, take your body weight in kg and multiply by 32.5 to get the amount of water to aim for (in mls). We then need to factor in exercise, which we need to take our body weight in kg and multiply by 2.1 and this gives us how much water we should drink per 15 minutes of exercise. So for me, at 85kg, exercising for about at least hour per day, I aim for a total of at least 3 litres per day. More recent research has helped to shed some light on the dosage of electrolytes we should be aiming for per day.
- 4-6g sodium
- 5-5g potassium
- 400-600mg magnesium
This will include what we get from food but chances are that we might need some supplementary salt on top. Which is where we developed MNRL, a solution for ourselves for the lack of options in NZ that had lots of salt and not much else. For context, the blue Powerade mentioned earlier has 28mg sodium and 5.8g of sugar per serve. To get an equivalent sodium dose to MNRL we would need to drink almost 36 bottles! That’s 207g of sugar and god knows how much blue, petroleum based colouring. Better living everyone!
I hope this helps shed some light on a bit of a tricky subject, looking forward to diving head first down some deep, deep rabbit holes in the future blogs. Stay tuned!
