Tag: hydration

  • The Problem With Starting Your Ergo Dehydrated.

    The Problem With Starting Your Ergo Dehydrated.

    How to START hydrated and why that’s so important.

    Sharing original article from Andy Blow, Precision Hydration.  Medically reviewed by Dr Tamara Hew-Butler. Precision Hydration support our newsletter subscribers with 10% off all purchases, when you use the discount code; Faster10 at checkout. www.precisionhydration.com

    The benefits of starting exercise hydrated

    Much of the literature on hydration has focused on what athletes should drink during exercise, but your hydration status before you start exercising can have a huge impact upon your athletic performance…

    When people talk about hydration, most of the time it’s about what and how much athletes should drink during exercise.

    These are clearly important questions, but your performance is also massively influenced by how hydrated you are when you start exercising in the first place. Drinking a strong electrolyte drink to optimise your hydration status before long, hot or really hard training sessions and events can significantly improve your performance.

    We call this “preloading” and the practice has been widely studied in the last 20 years or so, both with astronauts and athletes. Whilst there’s not a completely bullet proof consensus on the subject – there rarely is – there’s strong evidence that taking in additional sodium with fluids before you start sweating is effective in promoting increased acute fluid retention and in improving endurance performance, especially in the heat. 

    This blog aims to give you a more solid understanding of what you can do to arrive at the start of your next event optimally hydrated.

    What are the benefits of preloading?

    Once you begin sweating you’re generally going to be fighting a losing battle against fluid and electrolyte loss, so starting off properly hydrated can be extremely beneficial. When you’re properly hydrated you have a larger reservoir of fluid to draw from over time than if you’re dehydrated.

    Starting well hydrated has other benefits too. Optimal hydration maximises your blood volume and this helps general cardiovascular function and your ability to dissipate the heat produced by your working muscles. This reduces fatigue and enables you to maintain your performance for longer.

    Despite the relatively obvious benefits of starting exercise well hydrated, a recent study of over 400 amateur athletes showed that around 31% of them were turning up to training sessions (and, in some cases, competitions) dehydrated!

    In amongst the data there were strong indications that this was very likely to be compromising their performance. This will probably seem like common sense, especially if you’ve ever tried exercising when you know you’re a bit ‘dry’. Who in their right mind would want to start exercising hard in a dehydrated state if they’re trying to perform at their best?

    The problem with starting exercise dehydrated

    This study certainly backs up previous work I’ve read on the subject and the kind of things we’ve seen over many years working with athletes in different scenarios. It’s certainly not uncommon to see people only really thinking about hydration once they turn up to a session rather than preparing in advance. 

    Often this just happens because those of us who are not full time athletes are running around flat out between workouts and aren’t always able to think about preparing properly for them 100% of the time. That’s just life.

    But it can also be a problem for full-time athletes when training two or more times a day, or at times when they’re just under a very high total training load. That’s because uncorrected dehydration from a prior training session can make it’s presence felt when the next session gets underway. This blog addresses how to optimise your recovery by hydrating properly.

    Although athletes turning up to training a bit low on fluids is relatively common, it’s generally less of an issue before major competitions. That’s not to say that turning up to an event dehydrated never happens, I’m sure it does.

    The dangers of overdrinking and hyponatremia

    But, because most athletes care a lot about their performance in big events, there’s a tendency to increase fluid intake before the big day because extra priority is placed on all aspects of last minute preparation.

    A 2019 study found that 14% of 63 ultrarunners started the 246km (153 miles) Spartathlon midly hyponatremic. 

    The irony of this extra emphasis on pre-event hydration is that quite a lot of athletes can go from slightly under-drinking before training to significantly over-drinking pre-competition and this can lead to a different set of problems!

    I’ve written about the common tendency to over-drink before races in the past and the bottom line is that it’s a very real problem that can potentially lead to hyponatremia (i.e. low blood sodium levels caused by inadequately replacing the sodium lost when sweating and further dilution by drinking plain water or weak sports drinks), something that can be pretty catastrophic for health and performance if it goes unchecked. A recent study found that 10% of athletes tested at the Ironman European Championships had hyponatremia, which shows you the extent to which hydration issues might be impacting performance.

    The idea of carb loading – i.e. maximising the amount of glycogen you have stored in your muscles and liver before a strenuous activity – is one that’s well researched and essentially universally accepted as a performance-enhancing tactic.

    OK, so sports scientists love to argue over exactly what and how much you should eat, and when exactly to shove it in your cake hole, but few sane athletes would argue with the principle that consuming additional carbohydrate calories (often combined with a tapering off in training load) in the final days before an event is a good idea.

    That’s because you can store up and subsequently use a lot of this energy later on when you need to dig deep and burn through large amounts of fuel during a long or hard effort.

    With hydration things are less clear cut than with carbs. As we’ve seen, many athletes do tend to increase fluid intake prior to important events or hard training sessions, with the vague notion that having more in the tank should result in better performance. But many unfortunately over do it in the process and this is harming their performance.

    The importance of sodium for hydration

    But, can you actually store fluid over and above being normally hydrated and, if so, does it help to do so?

    The answer has a lot to do with not just how much water you drink, but with how much sodium you consume with that water as it’s this electrolyte that plays a key role in retention of fluid in the body and in the bloodstream in particular. For more on why sodium is crucial to staying hydrated and maintaining your performance, you may want to read this blog.

    In a nutshell though, without the right amount of sodium in your pre-exercise drinks, drinking lots of water will do you a fat lot of good. The importance of sodium to hydration and maintaining your performance was further proven by research conducted at NASA at the end of the 20th century.

    NASA astronauts hydration study

    NASA’s astronauts were commonly found to be suffering with low blood pressure because they were losing bodily fluids (and therefore blood volume) during their time in microgravity. One NASA paper I read suggested that astronauts live with as much as a 3-4% deficit in total body fluid levels during a typical mission. It was causing them to feel weak, light headed and even to black out on re-entry or once they landed back on terra firma. That’s not something you want to be dealing with when you’re trying to land a rather expensive space craft! 

    To combat this, NASA tested lots of drinks containing different carbohydrates and electrolyte mixtures and found that the more sodium you put in a drink, the more effective the drink would be at being retained in the body and bloodstream and correcting dehydration.

    On top of the work by NASA, there have been a number of scientific studies conducted into the idea of athletes ‘preloading’ with sodium and fluids prior to exercise in the last few years and the key findings from this work were summarised in a paper back in 2013.

    This review article essentially came to the same conclusion as NASA that sodium preloading with a drink strong enough to stimulate fluid retention in the blood stream, but not so strong that it caused other knock on issues, does seem to improve endurance performance. 

    As I mentioned, a higher blood volume means an easier time for your cardiovascular system when you’re exercising and also a bigger reservoir of fluids available to ‘lose’ through sweating if you need to cool down, as is the case when working your muscles hard and producing lots of metabolic heat.

    However, due to the mechanisms that control fluid and electrolyte balance in the body, any attempt to preload with plain water inevitably just leads to more trips to the bathroom as your body tries it’s best to avoid an excessive dilution of your blood sodium levels, which would lead to hyponatremia if unchecked.

    How to preload effectively

    It’s about striking a balance between being aggressive enough to drive some extra fluid retention in your blood stream without this leading to gastro-intestinal issues or excessive fluid build-up making you feel bloated and sluggish.

    Typical sports drinks – which generally contain ~200 to 500mg of sodium per litre – simply don’t cut it when it comes to preloading as they’re just way too dilute to make a meaningful difference to blood volume. The reality is it’s not vastly different from drinking water.

    At the other extreme, most of the scientific studies that have been conducted in this area have looked at using extremely strong electrolyte drinks containing ~3,600mg of sodium per litre. That’s like drinking a bag of saline solution that would normally be put into you via an IV! Whilst this has been shown to be highly effective at boosting blood plasma volume, it’s has a tendency to cause upset stomachs, sickness or diarrhoea – something that is obviously very counterproductive when you’re trying to improve your performance!

    One study back in 2014 looked at the effectiveness of 4 drink concentrations – Water, 1,380mg/l, 2,750mg/l and 3,680mg/l – to compare the effect they had on blood volume pre-exercise v how much sickness and diarrhoea they caused.

    The athletes drank a set amount (17ml per kg of body weight, so about 1.2l for an average sized 70kg athlete) of each of the drinks and the more sodium that was in it, the more blood volume was increased, as you’d expect. But with the strongest drink, 6 of the 8 athletes experienced diarrhoea compared with zero issues with the 1,380mg/l drink and plain water.

    That paper was of real interest to me as at Precision Hydration we’d already been experimenting with different concentrations of drink to use for preloading. I’d had lots of GI problems when trying 3,000mg/l+ drinks, so was already using less strong stuff and I was still finding it beneficial, so it was good to get some scientific confirmation that we were on the right track.

    In the end we settled on a strength of 1,500mg/l (32oz) for our preloading drinks and these are available in the all-natural PH 1500 drink mix format as well as low-calorie H2Pro Hydrate 1500 effervescent tablets. 1,500mg/l seemed to be the ‘sweet spot’ in that it’s very palatable and easy on the gut (we never get comments about stomach upsets from using it) whilst still being effective at boosting your blood plasma volumes and getting you optimally hydrated before you start sweating.

    If you want to test whether preloading improves your performance, follow this protocol before your next long/intense training session or B-race.

    Preloading with PH 1500:

    • Drink 1 x PH 1500 with ~500ml (16oz) of water the evening before your activity.
    • Drink 1 x PH 1500 with ~500ml (16oz) of water about 90 minutes before you start. Finish your drink at least 45 minutes before you start to give your body time to fully absorb what it needs and pee out any excess.
    • Drink the PH 1500 in water you’d have drank anyway to ensure you don’t overdo it. The circa symbol (~) before the fluid total is key here as different athletes will drink differing amounts – for example, more petite athletes might typically drink less than larger athletes. One size won’t fit all, so use some trial and error with these guidelines to help work towards what is best for you when preloading. 
    • DON’T just drink lots of water in the build-up to a race. You can end up diluting your body’s sodium levels before you start, increasing the risk of hyponatremia.

    Why you should preload

    • Boosting your blood plasma volume before intense exercise is a proven way to enhance your performance, especially in hot conditions.
    • Having more blood makes it easier for your cardiovascular system to meet the competing demands of cooling you down and delivering oxygen to your muscles.
    • PH 1500 is very effective at increasing your plasma volume as it contains 3x more sodium than a typical sports drink. That extra sodium helps to pull water into your bloodstream and keep it there. This may allow you to get away with drinking considerably less in shorter/harder events where previously they would have had to try to consume more on the move (not easy when you’re flat out!). It can also help reduce the amount of times you need to pee before you start.
    • Preloading with PH 1500 can also help you avoid/alleviate muscle cramps, especially if you’re prone to suffering from them late on in events and especially when it’s hot. 89% of athletes with cramp who try preloading PH 1500say that it solves their problems.
    • You can’t preload anywhere near as effectively with weaker sports drinks as you’ll lose a large proportion of the fluid as urine. Or it’ll slosh around in your stomach without being properly absorbed. 

    Precision Hydration support our newsletter subscribers with 10% off all purchases, when you use the discount code; Faster10 at checkout. www.precisionhydration.com

    If you’re looking for a way to optimise your performance then testing sodium preloading is definitely worth a try. If you have any questions about how to preload effectively or need help optimising your approach, drop us an email.

  • Importance Of Sodium & Water In The Body For Peak Performance

    Importance Of Sodium & Water In The Body For Peak Performance

    Many of us are lucky enough to be able to train on the ergo during lockdown, yet often training indoors can be a hot and sweaty event. It’s especially important to make sure your hydrated appropriately. The following article from Abby Coleman, explains more about the importance of sodium in your hydration strategy.

    I personally use Precision Hydration (PH) products, and PH are proud support Masters Rowers around the world, with their hydration needs. Use the code FASTER10 at checkout, to receive 10% off your purchase.

    How are sodium and water balanced in the body?

    By Abby Coleman Medically reviewed by Dr Raj Jutley. Original article can be found on the Precision Hydration website.

    Our bodies enjoy balance and will strive for equilibrium to help ensure that our sodium and water levels remain at a constant level. Why link sodium and water together?

    Well, the two are a double act (a bit like Ross and Rachel, Ant and Dec, the Chuckle Brothers, and any other legendary double-acts you can think of) in that water acts to hold the sodium ion in the body, so we must look at the two together when it comes to achieving the correct balance.

    But how does the body go about finding that all-important balance? We take a look…

    How sodium and fluid are balanced in the body

    The kidneys are our most important homeostatic control point (i.e. a bit like the heating control in your home) for both sodium and water.

    The balance happens in the kidneys with sensors from various parts of the body providing feedback with the end goal being preserving the plasma osmolality (saltiness) tightly between 275-300 mOsm/kg and sodium levels between 135-145 mEq/L. Osmolality, by the way, is how much of one substance is dissolved in another substance, and in humans the most important substance contributing to osmolality happens to be sodium. 

    When plasma volume or sodium concentration gets too high (osmolality increases)So, volume sensors in the heart, blood vessels, and kidneys detect when the body’s sodium or water levels get too high, and set in motion processes which lead to their greater excretion through the kidneys.

    In contrast, when blood plasma volume or sodium concentration becomes too low (osmolality decreases), the sensors trigger processes which increase their reabsorption through the kidneys.

    Both functions are actioned and regulated by the body’s endocrine system – a complex chemical messaging system made up of feedback loops of hormones.

    Because osmolality is exquisitely sensitive to the volume changes, any alterations in water has important effects. Which brings us to water balance…

    I personally use the Precision Hydration 1500 mix before and during training.

    Water balance in the body

    Humans are a soggy bunch and water makes up ~50 to 70% of our body mass, depending on our age, gender and body composition.

    Water is obtained mostly through consumption but also via our internal metabolism (e.g. the breakdown of glycogen), and it’s lost in urine, the gastrointestinal tract, sweat, and through the respiratory tract during breathing.

    Put simply, water balance is achieved by ensuring that the water we consume in food and drink is equal to that of excretion.

    But what happens when we take on too little or too much water?

    Too little water in the body

    A decrease in total body water, perhaps due to not drinking enough, excessive urination, sweat production, blood loss, diarrhea or vomiting, pushes the body to find ways of conserving fluids.

    Depending on the cause of water loss the body may need to conserve sodium as well.

    For instance, blood loss from a trauma will see sodium (in blood) and water (in blood) lost in equal proportion, and the body must try to retain both. Whereas in dehydration you lose proportionately more water than sodium, so the osmolality of your plasma increases and the body must conserve water, but not sodium.

    The hormone responsible for regulating the body’s retention of water is the antidiuretic hormone(ADH), also known as vasopressin.

    ADH is secreted by the hypothalamus, a kind of regulator in the brain for many bodily systems in response to an increase in plasma osmolality, decreased blood volume, decreased blood pressure and/or stress. The hormone acts on the nephrons of the kidneys (which basically produce urine, and remove waste and excess substances from the blood) and facilitates greater reabsorption of water by dramatically increasing the water permeability of the cell walls (i.e. how much water those cell walls let through).

    As a result, the passive movement (no energy required) of water out of the kidney back into the bloodstream is increased, and the urine produced is small in volume and concentrated.

    What about thirst?

    Whilst the kidneys can conserve water, they can’t do anything about producing more, so for that reason we must drink. Water intake is regulated by thirst; the stimulus for which, like ADH, is an increase in plasma osmolality (as little as 2-3% gives a strong desire to drink) or a decrease in blood volume.

    The combined effect of water retention (thanks to our good friend ADH) AND increased water consumption leads to an increase in blood volume and subsequent restoration of fluid balance in the body.

    By increasing blood volume, ADH also plays a role in reducing plasma osmolality (and therefore sodium concentration).

    Too much water in the body

    In a scenario where there is an increase in our total body water, plasma osmolality falls due to the relative decrease in sodium concentration.

    So, under these conditions, water moves out of the extracellular fluid into the body cells to try and maintain balance, which causes them to expand.

    Receptors within the cells respond to this swelling by signalling to the hypothalamus to slow down the secretion of ADH (‘stop conserving water, we have enough!’).

    Less circulating ADH means less aquaporin-2 channels get inserted into the kidneys’ walls and there’s a reduction in the amount of water reabsorbed into the blood. With fewer channels available for removal, a greater volume of water moves undeterred through the kidneys and is subsequently excreted in the urine. 

    The outcome? A reduced blood plasma volume, an increase in plasma osmolality, and urine which is diluted and large in volume (aaah, sweet, sweet relief as fluid balance is restored again).

    WAY too much water in the body

    An excessive overconsumption of water can be hugely counterproductive and produce the potentially fatal medical complication of hyponatremia (low sodium concentration of the blood).

    There are a few different causes of hyponatremia, but the one which affects athletes most frequently is the dilution of sodium levels driven by drinking TOO MUCH or ‘water intoxication’. 

    In an attempt to restore water balance, the body goes into overdrive pulling water out of the bloodstream and into the body cells, causing them to swell irrationally and damage or destroy cellular structure, thus disrupting normal cellular function. When this occurs in the brain cells the condition can escalate from confusion to seizures, coma or even death.

    The risk of hyponatremia is in part why drinking to thirst is pretty sound advice during everyday life and shorter, less intense activities where you’re not sweating much – and also why listening to your body’s signals is important.

    Sodium balance in the body

    Sodium is the main substance dissolved in the body, so it mostly determines the osmolality of plasma.

    Sodium plays a key role in every cell in the body, particularly nerve and muscle function where deficiencies or excesses become noticeable first, There are no body stores for so what you lose through the gut, sweat and urine, you must ingest – as simple as that.

    Just like water, sodium balance is maintained very cleverly by the kidneys adjusting the amount of sodium it filters, reabsorbs and excretes depending on whether the body is in deficit or excess.

    Too little sodium in the body

    A depletion of sodium, such as through extreme sweating (particularly if a person’s sweat sodium concentration is high) and/or a chronically low sodium diet, gives rise to low plasma volume, which in turn leads to low blood pressures.

    These low blood pressures throughout the cardiovascular system are recognised via baroreceptors (pressure sensors in the blood vessels which detect the pressure changes via changes in tension of the walls).

    These cause a decrease in the fancily named ‘glomerular filtration rate’ (the volume of fluid filtered through the kidneys), which is key because the less fluid which passes through the kidneys means less opportunity for sodium to be lost through urinary excretion.

    In addition, the fluid which is filtered by the kidney undergoes greater sodium reabsorption. The hormone responsible for regulating this sodium reabsorption is aldosterone, a steroid hormone secreted by the adrenal glands. The reabsorbed sodium is followed back into the blood by water and, as a result, blood volume, salt levels and blood pressure all rise.

    It’s important to note that aldosterone’s release is regulated by the renin-angiotensin hormonal system (RAS) which is responsible for managing blood pressure, fluid and electrolyte balance, as well as vascular resistance.

    In the event of sodium depletion, the kidneys produce renin, a peptide hormone that initiates a hormonal cascade that ultimately produces angiotensin II. It is angiotensin II which, once in the blood, stimulates:

    • thirst
    • the peripheral arteries to tighten and increase cardiac output, resulting in an increase in blood pressure
    • a decrease in glomerular filtration rate, resulting in water retention
    • the adrenal cortex to produce aldosterone.

    Renin-Angiotensin System

    1. Increased renin secretion (from kidneys)
    2. Increased plasma renin concentration
    3. Increased plasma angiotensin I concentration (from angiotensinogen)
    4. Increased plasma angiotensin II concentration
    5. Increased aldosterone release (from adrenal cortex)
    6. Increased plasma aldosterone concentration
    7. Stimulates sodium reabsorption in the kidney

    Too much sodium

    With the Western diet, it’s not difficult to consume a little too much sodium these days. For centuries man was deficient hence he traded in salt but now the pendulum has swung the other way with hidden sodium in our diets. An excess of sodium in the body isn’t recognised by alterations in sodium concentration as you might think, but rather by the increase in plasma volume as a result of the increased sodium (remember where sodium goes water goes too).

    The elevation in blood volume causes an increase in the tension in the receiving chambers of the heart (atria), which in turn initiates the release of atrial natriuretic peptide (ANP); a hormone which is both produced and stored in the cells of the heart.

    Once in circulation, ANP affects the kidney by increasing the glomerular filtration rate (the rate at which blood passes through the glomeruli in the kidneys) which induces profound natriuresis (increased sodium excretion) and diuresis (increased water excretion).

    It also induces the dilation of the blood vessels to limit the rise in blood pressure and inhibits the secretion of aldosterone, by reducing renin production, thus actively preventing sodium reabsorption from occurring.

    This is quite a meaty and complex topic area (congratulations if you made it this far in the blog), but what hopefully comes through loud and clear is that:

    1. Sodium and water travel together and their ‘saltiness’ must be tightly regulated.
    2. Their balance is ultimately in the kidney.
    3. Feedback to the kidney is from ‘pressure and saltiness’ receptors in the heart, blood vessels, kidneys and brain.
    4. Regulation is a finely balanced and complex interplay between several hormones depending on whether water or sodium is less or more. 

    Ultimately, the kidneys and the hormonal system play a vital role in helping the body to find equilibrium when it comes to sodium and fluid balance.

    Helping these systems out by tailoring what you consume – in terms of sodium and fluid in relation to your individual losses – should therefore start to make a bit more sense from now on.

    Original article link

  • Things I’m testing & trying out in Rowing this year.

    Things I’m testing & trying out in Rowing this year.

    Every year I take a look at a few things to experiment with. All with the aim of improving my personal performance. In this post I’m sharing what I’m experimenting with for rowing, across different aspects, and over the coming months, I will share updates in my newsletter.

    New Carbon Pack from Filippi

    I’ll be testing the new ‘Carbon Pack’ from Filippi Boats with the Filippi F22 single scull. I first learnt about these developments in late 2020, when I spent some time with David Filippi at the Italian Championships. I’m curious to see Filippi’s new developments in carbon fibre footplate, seat deck interface, rigger and gate technology. More information will be revealed as I share the process of the new boat build and interview David Filippi on the Faster podcast about the new technology.

    Clothing

    Testing 776BC rowing clothes for comfort, durability and how their ‘Motion Technology’ works. The 776BC Motion System highlights key biometric markers and lines on the body. The aim is to show how you’re moving whilst rowing on the ergo or in the boat. To achieve this, 776BC developed a motion sensor app, that you can use to film the session, and observe how the biometric markers line up vs the desired technique.

    I have order some 776BC customised kit for a few willing masters and juniors to try at my club. Will update how the kit looks, feels and how it is to work with the Motion App for filming and providing feedback.

    Hydration & Pre-Loading

    I’ve been paying more attention to how much and what I’m drinking  during training, especially with the increase in time on the ergo, and this year I will be experimenting with how my performance is influenced by how hydrated I am when I start exercising.

    Precision Hydration have a protocol they call, ‘preloading‘ and the practice has been widely studied in the last 20 years. There’s strong evidence that taking in additional sodium with fluids before you start sweating is effective in promoting increased acute fluid retention and in improving endurance performance, especially in the heat.

    I will be working with the team at Precision Hydration, to dial this in over the coming months and I’ll share updates along the way.

    Monitoring HRV

    On the advice of masters champion, Greg Benning, I will be monitoring my Heart Rate Variability (HRV), and using this metric to measure my response to, and readiness for training. I’ll be using and comparing the Oura Ring and Elite HRV app & heart rate belt.

  • Why sodium is crucial to athletes performing at their best

    Sharing an interesting article on why sodium is important for Masters Rowers to perform at our best. Original article by Andy Blow and medically reviewed by Dr Tamara Hew-Butler.

    Disclosure: Precision Hydration support subscribers to the Faster newsletter with 10% off all purchases.

    Why sodium is important

    Sodium plays a key role in how your body functions as it helps maintain fluid balance and cognitive function, so it’s important to replace the sodium you lose to some extent when your sweat losses really begin to mount up.

    A 2015 study found that athletes who adequately replaced the sodium lost in their sweat finished a middle distance triathlon an average of 26 minutes faster than those who didn’t.

    Whilst that sort of performance gain isn’t going to be possible for everyone, it does highlight the potential impact of getting your hydration strategy right.

    Your body contains lots of water – 50-70% of it is made up of the stuff in fact, depending on the amount of muscle and fat that you have. Around a third of that water exists outside your cells, in extracellular fluids like your blood.

    What does sodium do?

    The main electrolyte in this extracellular fluid is sodium and much of your body’s total sodium reserves are found here. This makes it rather ‘salty’ and the total volume of extracellular fluid in your body is directly related to the amount of sodium you have on board at a given time. So, more sodium equals more fluid; less sodium means less fluid.

    As well as maintaining fluid balance, sodium plays an important role in the absorption of nutrients in the gut, maintaining cognitive function, nerve impulse transmission and in muscle contraction. Basically, it’s pretty darn important.

    Most of the sodium we consume is in the form of sodium chloride, or the common table salt found in food and drinks.

    We take salt for granted these days as we’ve developed ways to make it widely available. But in the past wars were fought over access to and the control of salt, which gives you a pretty big clue as to its importance to life!

    Because your body can’t produce or store it beyond a certain point, you need to consume sodium every day to keep your levels topped up.

    Individual differences in sweat sodium losses

    Sweating is the main way athletes lose sodium and fluids during exercise. That’s basically why those of us who train regularly have different needs when it comes to replacing sodium than those who don’t.

    Everyone loses a different amount of sodium in their sweat. At Precision Hydration, we see athletes who lose from as little as 200mg of sodium per litre of sweat to as much as 2,000mg/l. I personally lose ~1,800 mg/l and I often suffered from hydration issues in hot climates as a result. It was my personal search for a solution that led to me founding the company.

    Sweat rates also vary from person to person of course; and from situation to situation for any given person (from almost nothing in cooler conditions and at low intensities, to several litres per hour during intense exercise in the heat).

    When you combine differences in sodium concentration with those in sweat rates, the potential variance in the total net sodium losses experienced from one athlete to another can be really significant, especially over a middle or long distance triathlon.

    And, in a lot of cases, those losses are many times higher than someone who’s not sweating on a regular basis. This is why the standard government guidelines for sodium consumption should be viewed cautiously by athletes. It’s more than possible to lose the daily 2,300mg of sodium recommended by the existing government guidelines in just 1 hour of exercise, if you’re sweating heavily and you’re sweating out lots of sodium. Your loses during a longer period of exercise really can be massive.  

    What happens when sodium losses mount up?

    It’s impossible to nail down the exact point at which sodium (and fluid) loss through sweating becomes a problem for an athlete. But, it’s clear that when losses reach a certain point, the effects can be detrimental to your performance.

    Your blood volume is gradually reduced as your sweat losses increase. That’s because sweat is drawn from your blood plasma. This increases the strain on your cardiovascular system, making it harder to pump blood to your skin to cool you down and to your working muscles.

    Other issues such as a general feeling of fatigue and muscle cramps can also be experienced if losses are allowed to go uncorrected for long enough, or if significant imbalances between fluid and sodium are allowed to occur. 

    Up to a certain point, taking in plain water is enough to mitigate sweat losses. But, as those losses start to mount up, you need to replace sodium too in order to avoid your blood becoming diluted.

    This is a potentially disastrous condition called hyponatremia, which can certainly ruin your race and, tragically, has even been fatal on occasion.

    How much sodium should you replace when sweating? 

    Because sweat/sodium losses are so individual, any generic guidelines on the replacement of sodium and fluid should always viewed with suspicion.

    Having said that, figuring out whether your net losses are likely to be low, moderate, or high can be a great starting point for honing in on the level of sodium and fluid replacement that’ll work best for you in different circumstances.

    The two main inputs that drive your personal net sodium losses are…

    1. The total amount you sweat. This is a factor of your sweat rate and the number of hours you spend sweating during a given timeframe.
    2. Your sweat sodium concentration. i.e. how much salt you lose in your sweat.

    Figuring out approximately what these are is a sensible place to start.

    Calculating your sweat rate can be a bit awkward, but here’s a guide to help you get you to a reasonable estimate of how much you’re sweating per hour.

    Your sweat sodium concentration is largely genetically determined and doesn’t vary much at all which means that, whilst you can only find it out by getting your sweat tested, you only really need to get tested once in most cases.

    Precision Hydration offer a free online Sweat Test that’ll help you get started with understanding your losses and refining your hydration plan through some good old fashioned trial and error in training.

    Precision Hydration supports subscribers of the newsletter, with 10% off all purchases when you enter the code below at checkout.

    Enter code: FASTER10 at check out www.precisionhydration.com

    Check out the podcast interview with Andy Blow on Faster

    https://anchor.fm/s/1f7219c8/podcast/rss