Could a Higher Salt Intake Benefit Performance? Here’s the Expert Take
The official guidance leaves little room for interpretation: too much salt is bad for you. It raises blood pressure, increases your risk of cardiovascular disease and long-term could lead to a fatal stroke or heart attack.
And yet, there’s a growing number of dissidents calling for a rethink – most notably Stanford professor and podcaster Andrew Huberman, plus the 112 million or so people posting under #SaltWaterTrend on TikTok. Like grass-fed beef and butter before it, the pro-salt movement has reopened the debate over whether the tabletop staple – and the mineral sodium in particular – can help or hurt your health.
But it’s not just podcasters and TikTokers: in October 2020, a headline-grabbing study published in the European Heart Journal noted that a salt intake of 10g to 12.5g a day – twice the limit currently recommended in the UK – was associated with an increase in life expectancy.
‘All my life I was a salt-reduction evangelist,’ said the study’s lead author, Franz Messerli, a cardiologist at the Swiss Cardiovascular Centre at Bern University in Switzerland. His findings forced him to challenge this belief. ‘I asked myself, “What is the advice we give about salt really based on?”’
Before Professor Messerli, there was James DiNicolantonio. In 2017, the US doctor of pharmacy and cardiovascular research scientist published his book The Salt Fix: Why The Experts Got It All Wrong – And How Eating More Might Save Your Life.
Having reviewed more than 500 papers on salt consumption, blood pressure and heart disease, he concluded that, ‘The vast majority of us don’t need to watch our salt intake. In fact, for most of us, more salt would be advantageous for health.’
Speaking to Men’s Health seven years later, Dr DiNicolantonio is steadfast in his view that salt guidelines need an urgent rethink. ‘Approximately 80% of people with “normal” blood pressure (between 90/60mmHg and 120/80mmHg) aren’t sensitive to the blood pressure-raising effects of salt at all,’ he says. ‘Even among those with full-blown hypertension, about 55% are totally immune to salt’s effects on blood pressure.’
He also insists that the western world’s addiction to caffeine, a dehydrating diuretic, is depleting our levels further. ‘Here’s something that’s never talked about,’ he says. ‘Caffeine and coffee are one of the biggest salt wasters out there. It causes a tremendous loss of salt, excreted in our urine, even if it doesn’t lead to a significant loss of fluid.’
Four cups of coffee will cause about 1,200mg of sodium loss, he explains, which equates to around half a teaspoon. ‘Now, if you’re exercising for an hour a day, which is what most guidelines recommend, you need to be consuming around 4.7g to 5g of sodium, which adds up to around 12.5g of salt, just to maintain balance.’
For the two in 10 people who are ‘salt sensitive’, and therefore more vulnerable to hypertension, Dr DiNicolantonio argues salt itself isn’t to blame. ‘Many other things cause people to be sensitive to salt, such as refined carbs and sugars, which elevate insulin levels, causing the body to over-retain salt. We’ve got to fix that.’
Against the Grain
This shift in perspectives has put brands on notice. This year saw the launch of Cadence, a salt-based canned drink, created by Ross MacKay, founder of plant-based food start-up Daring, and George Heaton, of British luxury fashion house Represent.
‘George and I were both training intensively while running our businesses and felt existing hydration products didn’t meet our quality or format expectations,’ MacKay tells MH. Traditional electrolyte formulas, he says, offer inferior mineral ratios and are crammed full of sugar, sweeteners and stimulants. The solution? Salt.
According to the brand’s mission statement, Cadence hopes to ‘change the story of salt’, chiefly the idea that we need less of it.
‘Salt has been demonised largely due to its association with high blood pressure and cardiovascular disease when consumed in excess,’ MacKay explains. ‘This negative perception has overshadowed the fact that salt, in proper amounts, is essential for bodily functions, especially for athletes who lose significant amounts through sweat.’
Cadence is already on the menu at Soho House, where one 250ml can contains 190mg potassium chloride, 295mg magnesium lactate and 500mg of sodium chloride (salt).
This summer, supplement brand Puresport – an early player in the CBD market – released its range of Ultra Electrolytes, with 1,000mg of sodium per serving. At the start of the Euros in Germany, ‘pickle juice’ was trending, heralded as the new mineral-rich recovery remedy.
Could salt be the marginal gain you’ve been missing? Are we all at risk of chronic dehydration, thanks to overzealous government guidelines? Or could this trend risk pushing our delicate electrolyte balances off-kilter, to potentially dangerous effect?
To understand how we arrived at this inflection point, let’s first put salt under the microscope to understand what it is, and why we need it.
Why We Need Salt
Technically a metal, sodium (represented by the symbol ‘Na’ on the periodic table) is a type of mineral that cannot be produced by the body, so is an essential component of the human diet. In its most common form, you’ll find salt packaged as sodium chloride (NaCl) – aka table salt – at a ratio of roughly two parts sodium to three parts chloride. One teaspoon of salt contains about 2,400mg of sodium.
While not all salt is created equal (less heavily processed versions such as rock, sea, pink and Himalayan might contain more nutrients, yet these are usually negligible and can be sourced from other foods in your diet), they all have the same effect on your blood pressure as the cheap stuff you’ll find in greasy spoons.
So apart from adding flavour, what’s it good for? Well, sodium, along with other electrolytes, plays a crucial role in maintaining homeostasis in every cell in the human body.
It contributes to the release of digestive secretions and controls the absorption of amino acids, glucose and water. It ensures sufficient blood volume, pressure and safe passage of fluid through the circulatory system (perfusion) to support good organ function.
When we exercise, sodium is vital for the stimulation of muscle and nerve cells; it also increases our thirst stimulus and reduces the production of urine. In short, it’s good for a lot.
Excess salt, however, has been shown to adversely affect the vasculature, heart, kidneys, skin, brain and bones due to heightened inflammation and oxidative stress. At the other end of the spectrum, a low intake has been associated with an increased risk of cardiovascular events and death. As such, it’s earned Goldilocks status: not too much, not too little.
How Salt Can Harm
Action on Salt, a charity founded by Graham MacGregor, a professor of cardiovascular medicine at Barts & The London Hospital, has been banging this drum since 2003. Its work led to a pioneering voluntary salt-reduction programme in the UK that’s seen population-wide reductions in salt intake, blood pressure and stroke and heart disease mortality rates. But these initial gains are starting to backslide – and the issues are mirrored worldwide. Last year, the World Health Organization (WHO) reported that the world is falling short of achieving its global target of reducing salt intake by 30% by 2025.
And the likes of Professor MacGregor and Sonia Pombo, campaign lead and nutritionist at Action on Salt, fear that the message spread by the likes of Dr DiNicolantonio – as well as ‘cleverly marketed’ hydration drinks – could be eroding these early wins further.
‘Population-level interventions are here for a reason,’ says Pombo. ‘Research shows that a blanket approach to reducing salt is more effective than an individualised approach.’ A can of Cadence contains around half a gram of salt, ‘so not a huge amount’, she says. ‘But when you realise we shouldn’t consume more than 6g per day – that’s a maximum, not a target – you realise it can add up.’
Day to day, Pombo says, we’re simply consuming too much. ‘It’s in bread, cheese, biscuits. It’s probably in your protein shake. It’s in everything.’ The average salt intake among English working-age adults is currently 8.4g a day, well above the current guidelines.
A 2022 report by the British Heart Foundation (BHF) spelled it out: if every adult in the UK met the WHO salt consumption guidelines of no more than 5g per day by 2030, within five years we’d see 1.4m fewer cases of high blood pressure, 135,000 fewer cases of coronary heart disease and 49,000 fewer cases of stroke. It’d also generate an estimated £11.4bn in savings through reduced use of the NHS. In other words, the NHS, BHF and WHO all agree: cutting down on salt will save lives and save money.
Blood, Sweat and Toil
At population levels, cautioning against salt might be sensible, but athletes should still take heed; the effects of low blood sodium are no joke.
Around the turn of the century, a group of keen marathon runners in the US were afflicted by a spate of mysterious ailments.
At the time, Art Siegel, an associate professor at Harvard Medical School, and Tamara Hew-Butler, an associate professor of exercise and sports science at Wayne State University, were studying hyponatraemia. This occurs when there’s an imbalance of sodium and water in your blood. Sodium helps maintain optimal blood pressure, keeping your muscles and nerves in working order. So when the blood concentration of this mineral plummets, you’ll know about it.
First, your fingers will swell. Next, your legs will start to feel heavy. Nausea and weakness follow, then confusion, seizures and, left untreated, potential loss of consciousness and death.
Dr Hew-Butler and Dr Siegel took notice when a number of runners collapsed mid-marathon. Assuming dehydration, they were hooked up to IVs to replenish fluids, only to then suffer seizures. Several required intubation, some slipped into comas, and one 28-year-old runner suffered what was termed a ‘brain death’.
Upon examination, it was discovered that they had all experienced hyponatraemia. However, subsequent research found that electrolyte loss (sweating out too much salt) wasn’t the culprit. Instead, this condition is caused by consuming far more water than is lost through sweat. This then dilutes levels of sodium in the blood.
And that is why electrolytes have earned cult status among endurance elites. When we sweat, water is drawn out of our cells, carrying sodium with it, which is then deposited on our skin or clothes. As sodium isn’t stored in the body, the only way to restock is via our diets.
That’s easily done when you’re grazing at your desk, but when you’re strapped to a triathlon bike or zipped up in a wetsuit, clocking several hours of non-stop exercise, you need to take a more proactive approach.
You also need to get personal. According to the team at Precision Fuel & Hydration, which has been helping elite and everyday athletes get race ready since 2011, the rate of sodium lost from sweat can vary up to 15 times between seemingly similar individuals.
‘It’s largely predetermined by your genetics,’ explains Stuart Anderson, a member of their athlete support team. ‘Some will lose as little as 200mg per litre of sweat, no matter the conditions. Some as much as 2,000mg per litre.
‘Salty marks on your kit or skin post-workout, feeling faint when standing up too quickly after exercise and experiencing muscle cramps during or after long training sessions are all signs you’re a salty sweater.’
Precision’s coterie of Ironmen, triathletes and ultrarunners believe a one-size-fits-all approach simply doesn’t work. Instead, they offer personalised hydration plans and a tailored mix of products to meet athletes’ individual needs. To better understand mine, I joined Anderson at bike shop Pearson Performance on a particularly muggy morning in south-west London for one of Precision’s signature ‘sweat tests’.
It takes just 45 minutes. Anderson sticks two small patches above my wrist, which run a barely perceptible current through my arm, causing localised sweating. After a few minutes, this liquid is drawn out of one of the discs and run through a machine, which then spits out a precise reading of the sodium lost per litre of sweat.
‘You’re just above average,’ Anderson concludes, talking through my results. ‘You lose 1,064mg of sodium per litre, making you a moderately salty sweater.’ Using this intel, combined with an algorithm-based questionnaire that scrutinises my workout habits, and the knowledge that I intend to tackle a 22.6km swim-run later this year, Anderson presents me with a personalised hydration strategy.
My plan: pre-hydrate with 1,500mg of sodium in half a litre of water 90 minutes before the start of my race, plus 30g of a caffeine energy gel 15 minutes before go-time; then sink 500ml of H²O, 500mg of sodium and 75g of carbs every hour I’m still chugging round the course.
It’s hard to argue with the granular detail that Precision has presented me with, and I’d be a fool not to incorporate its advice into my training. Yet it’s also hard not to get bogged down in the minutiae of it all. As Avril Lavigne would say, why’d you have to go and make things so complicated?
A Fair Shake
Rob Hobson, a registered sports nutritionist and author of Unprocess Your Life, agrees. His message: keep it simple. ‘If you want to know if you’re hydrated or not, just check the colour of your urine,’ he says. Light yellow is optimal. Totally clear suggests you’re overhydrated.
‘And unless you’re intentionally cutting almost all salt out of your diet and just eating garden salads, it’s very unlikely that your sodium levels will be so low that you need to supplement them with an electrolyte.’
Instead, he suggests we avoid obsessing over one single nutrient. ‘If you’re worrying that you consume too much salt, just try cutting down on junk food, cook more from scratch and make better food choices overall. If you do that, you’ll naturally reduce your salt intake.’
As for Dr DiNicolantonio, he does still advocate a daily electrolyte scoop first thing (‘I might take 800mg to 1,200mg of sodium with 250ml to 350ml of fluid before training just so I know I’m hydrated’) and pre-loading sodium 90 minutes before training (which he says can increase exercise endurance by over 50%). But he also sees merit in exercising in a ‘salt-depleted state’ to encourage adaptations so that you’re not so reliant on an optimal mineral solution pre-workout.
If, however, you’re staring down the barrel of an ultramarathon in the Sahara Desert or an Ironman in Hawaii, then fine-tuning your hydration strategy with a sprinkle of sodium, a dash of magnesium and a pinch of potassium could well make the difference between crossing the finish line or not finishing at all.
‘Endurance athletes often fall into the trap of thinking, “It’s supposed to be hard, I’m supposed to suffer” and push themselves to a point where they just fall off a cliff,’ says Anderson, speaking from experience. ‘But if your nutrition is correct, your sodium is correct and your fluid intake is correct, then maybe you don’t need to suffer quite as much.’
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