Well, as you may have noticed, it has been a touch warm recently, I have been feeling very pleased with the aircon units in clinic, plus down the beach twice a day for a swim on non-clinic days.
And Floyd showing off the jumping skills that made him the Dorset under 12 years old long jump champion.
But, heat at these levels is a challenge, especially for people whose health is not optimal.
The advice to “drink more water” is certainly sensible, but it is only part of the picture.
Hydration is not simply about replacing lost fluid. It is about replacing both water and the electrolytes that are lost through sweat.
In many situations, particularly during prolonged sweating, replacing electrolytes is just as important, and arguably even more important, than replacing water alone.
Electrolytes are electrically charged minerals that dissolve in body fluids and allow electrical impulses to travel throughout the body.
Every heartbeat, muscle contraction, nerve impulse and movement of fluid across cell membranes depends upon them. Even small disturbances can affect how we feel and perform.
Sweating is an incredibly effective cooling mechanism.
As sweat evaporates from the skin it removes heat from the body, helping prevent dangerous rises in core temperature.
However, sweat contains far more than water.
Each litre lost contains varying amounts of:
• Sodium
• Chloride
• Potassium
• Smaller amounts of magnesium and calcium
During prolonged exercise, gardening, manual work, golf, cycling, hiking or simply spending long periods outdoors in hot weather, these losses can become significant.
Or for those with already low levels of minerals, the extra sweating just drops them down to the point of symptoms.
Remember this from a few months ago
“Estimated prevalence of chronic latent magnesium deficiency (CLMD), represented by a serum magnesium concentration 0.85 mmol/L, was 67.8% in adults.”
Replacing only the water while failing to replace electrolytes gradually dilutes the body’s remaining mineral concentrations, making it increasingly difficult to maintain normal physiology.
Sodium often receives negative publicity because of the fear of high blood pressure.
Though as discussed, this is a fear unfounded for the majority of people.
Sodium is an ESSENTIAL mineral, you have to eat it.
Too much (and that means a huge amount) is an issue, but so too is too little.
So, let’s consider what the body will do, if it does not get enough?
Well, the kidneys will either let sodium out via urine or it will retain sodium by re-absorbing it.
The control of which is dictated by ALDOSTERONE.
If you do not have enough sodium, your adrenal cortex turns up ALDOSTERONE, and you RETAIN SODIUM.
And this has been demonstrated time and time again.
If you go on a low-salt diet (or in at the moment, you sweat lot and do not replace the sodium), your body will simply retain more sodium to maintain its reserves by increasing ALDOSTERONE by an average of 127%.
Not only that, low salt diets also INCREASE CHOLESTEROL (2.9%) and TRIGLYCERIDES (6.3%) and ADRENALINE (14%) / NORADRENALINE (27%).
Doesn’t sounds very healthy to me.
Sodium an essential nutrient also helps:
- Maintain blood volume
- Regulate fluid balance
- Support nerve signalling
- Enable muscle contraction
- Facilitate the absorption of glucose and water from the intestine
In fact, one of the reasons oral rehydration solutions are so effective is because sodium enables water to be absorbed much more efficiently from the gut than water alone.
This is why drinking large amounts of plain water during prolonged sweating is often less effective than consuming fluids containing appropriate amounts of sodium.
While sodium usually receives most of the attention, potassium is equally important, though much harder to get from your diet, as I discussed here:
3500 mg of potassium is a lot of fruit and vegetables.
And if you do not hit that target, and are losing potassium in sweat bad things can happen.
Potassium works alongside sodium to regulate electrical activity across cell membranes. It is essential for:
- Normal muscle contraction
- Heart rhythm
- Nerve transmission
- Cellular hydration
The sodium-potassium pump, found in virtually every cell in the body, continuously moves sodium out of cells and potassium into them.
This process consumes a remarkable amount of the body’s energy and underpins normal cellular function.
Without sufficient potassium, muscles become weaker, nerves function less efficiently and fatigue develops more readily.
Magnesium is involved in well over 300 enzymatic reactions throughout the body.
It contributes to:
- Energy production
- Normal muscle relaxation
- Nervous system function (blocks calcium entering cells)
- Electrolyte balance (via Na/K pump)
- Protein synthesis (via DNA polymerase)
Although only relatively small amounts are lost in sweat compared with sodium, ensuring adequate magnesium intake remains important, particularly during periods of increased physical activity and sweating.
Many electrolyte drinks focus almost exclusively on sodium (mainly because it is cheap).
However, because hydration depends upon multiple interacting minerals, our IN Health Electrolytes formula was developed to provide a broader nutritional approach, with higher than average potassium and a clinically meaningful dose of magnesium.
It combines Himalayan salt as a natural source of sodium and chloride with potassium citrate and magnesium bisglycinate.
The addition of malic acid and citric acid provides a refreshing lemon and lime flavour while also contributing to normal energy metabolism.
One heaped teaspoon gives you:
Currently, I am doing two, sometimes three heaped tea spoons daily, best sipped throughout the day.
Remember to dilate to your taste:
One of the biggest challenges during hot weather is sleeping.
We often think of sleep as something controlled entirely by the brain, but body temperature plays a surprisingly important role.
To initiate sleep, our core body temperature naturally falls by around half a degree Celsius.
This cooling occurs by increasing blood flow to the hands and feet, allowing heat to escape through the skin.
Warm summer evenings interfere with this process, making it harder to fall asleep.
Interestingly, research suggests everyone’s favourite amino acid, glycine may help.
Although best known as one of the major amino acids used to build collagen.
Glycine has been shown in several placebo controlled human studies to improve subjective sleep quality, reduce the time taken to fall asleep and improve next day alertness without causing morning grogginess.
Researchers now believe one reason for these benefits is that glycine enhances the body’s natural cooling mechanisms.
After crossing into the brain, glycine acts within the suprachiasmatic nucleus, the body’s master circadian clock.
It increases blood flow to the skin, particularly the hands and feet, allowing greater heat loss.
This results in a small reduction in core body temperature, helping create the physiological conditions needed for sleep.