Your Sweat Glands Are a Secret Weapon for Your Heart

You are probably carrying more sodium in your body right now than your heart wants. And your workouts may be feeling that strain — even if you feel fine. A review article published in April 2026 in Exercise and Sport Sciences Reviews makes a compelling case that sweating is one of the body’s most overlooked tools for clearing excess sodium and protecting your heart.

A quick note on what this paper is: it is a narrative review and hypothesis piece, not a clinical trial. That places it lower on the evidence pyramid than a randomized controlled trial or a large meta-analysis. Think of it as an expert road map — a well-reasoned argument backed by existing science, pointing toward where future research needs to go. The authors are clear about that distinction, and so are we.

With that said, the case they make is worth understanding. Nine out of ten American adults eat more sodium than recommended. The average intake is 3,550mg per day. The USDA guideline is 2,300mg. The American Heart Association’s ideal is just 1,500mg. Most people know too much sodium raises blood pressure. What fewer people realize is where that extra sodium goes in the body, how it quietly raises cardiovascular strain during exercise, and what a well-timed sweat session — or time in a sauna — can do about it.

The Problem With Sodium Goes Beyond Your Resting Blood Pressure

Most people think of blood pressure as the number they get at the doctor’s office. You sit still. The cuff squeezes your arm. A number comes out. That number matters. But emerging research suggests that blood pressure during exercise may be an even stronger predictor of future heart problems.

A meta-analysis (a study that pools and analyzes results from many individual studies at once) of more than 46,000 adults found that people with exaggerated blood pressure responses during submaximal exercise (think a brisk walk, a moderate jog, or a bike ride where you could still hold a conversation) had a significantly higher risk of cardiovascular events and death. That risk existed even when resting blood pressure and other heart disease risk factors were accounted for. In simple terms: how your blood pressure behaves while you are moving matters, perhaps even more than how it looks when you are sitting still.

A separate team of researchers at Florida State University put this into direct practice. In a 2020 study published in the Journal of the American Heart Association, participants spent 10 days on a high-sodium diet, averaging about 6,486mg of sodium per day. Compared to their normal-sodium baseline, their systolic blood pressure during moderate aerobic exercise rose by 8 points — measured in millimeters of mercury (mmHg), the standard unit for blood pressure, left over from the days when gauges used a mercury column to measure pressure in your arteries. Eight points may not sound like much, but that kind of repeated elevation during physical activity adds up to real cardiovascular strain over months and years.

High sodium works through several pathways at once. It reduces the ability of blood vessels to relax and widen during exercise. It makes the nervous system more reactive. It sensitizes the nerve signals that tell your heart to work harder when you move. And it triggers inflammation that compounds all of the above. Even a single high-salt meal can start reducing blood vessel function within 60 minutes of eating it — by limiting the amount of nitric oxide your vessels can produce. Nitric oxide is what tells your blood vessels to relax and open up. Less of it means more pressure.

Your Skin Is Storing Sodium Your Kidneys Can’t Fully Clear

Here is something most people do not know. Your kidneys are the main system for removing excess sodium from your body. But your skin — the body’s largest organ — is actually one of the biggest storage sites for it.

When you eat more sodium than your body needs consistently, significant amounts get stored in the deeper layer of your skin called the dermis. It gets bound to connective tissue there in a kind of “third compartment.” It is not circulating in your blood. Your kidneys do not see it the same way. It just sits there, accumulating over time.

Now here is where sweating becomes relevant. The sweat glands in your skin draw their starting fluid from that same dermal environment. When your sweat rate gets high enough, the body’s ability to reabsorb sodium back out of the sweat before it leaves the skin gets overwhelmed. Sodium exits with the sweat in meaningful quantities. It is a separate excretion pathway that operates independently of your kidneys — and it draws directly from that stored reservoir in your skin.

Sweating Intentionally: What the Numbers Actually Show

Different types of sweat-inducing activity remove different amounts of sodium per session. These numbers vary by individual — your fitness level, how acclimated you are to heat, and your genetics all play a role. But the range is worth knowing.

A moderately active person sweating for 60 minutes of exercise can expect to lose around 1,000mg of sodium. A 90-minute hot yoga session — where the hot, humid room makes evaporative cooling difficult and forces a higher sweat rate — has been shown to result in an average sodium loss of about 2,700mg. People doing physically demanding work in the heat can lose 4,800 to 6,000mg in a single shift.

For passive approaches, a 60-minute dry sauna session can remove approximately 1,000mg of sodium without any exercise at all. Hot water immersion (sitting in a hot bath around 104°F/40°C) produces similar results. These passive options are meaningful for people who cannot do high-intensity exercise due to joint problems, weight, or other limitations — they still get real sodium excretion and real cardiovascular benefit.

There is also a long-term benefit to regular heat exposure. Over about 10 days of consistent sessions, sweat glands adapt to produce more total sweat volume — which means more total sodium cleared per session over time. A landmark Finnish study following more than 2,300 men over 20 years found that those who used the sauna four to seven times per week had a 63% lower risk of sudden cardiac death compared to those who used it just once a week.

What to Know About Rehydration After Sweating

One thing the research is clear about: the goal of sweating intentionally is not to create a sodium deficit and then fill it back up with a high-sodium electrolyte drink. That defeats the purpose.

For most healthy people doing moderate exercise, plain water and regular food — seasoned to taste — is enough to rehydrate properly after a sweat session. The research authors specifically call out the widespread use of high-sodium electrolyte mixes as unnecessary for most exercisers. The pattern they describe is easy to fall into: you sweat, feel depleted, reach for something full of sodium, and put back exactly what your body just worked to clear.

There are situations where electrolyte support genuinely makes sense — long training sessions in the heat, endurance events, or high-intensity outdoor work where you are sweating heavily for extended periods and need to maintain performance during the session, not just after it. In those cases, what you choose for rehydration matters.

What This Means Practically

It is worth being honest about what this research does and does not prove. The Florida State University review presents a strong, well-reasoned hypothesis. The mechanism is clear. The epidemiological data is compelling. But the definitive clinical trial — one that directly tests whether regular sauna use or heat exposure chronically reduces exercise blood pressure over months — has not been completed yet. The authors acknowledge that. So do we.

Here is what the existing evidence does support clearly:

• Excess sodium raises blood pressure during exercise, even in otherwise healthy people. That elevation adds up to real cardiovascular risk over time.
• Your skin stores sodium that your kidneys cannot fully see or clear. Sweating gives your body a second pathway to remove it.
• Exercise in the heat, sauna, hot yoga, and hot water immersion all produce measurable sodium losses per session — ranging from around 1,000mg to more than 2,700mg depending on the activity and duration.
• These interventions also carry their own independent cardiovascular benefits: improved blood vessel function, lower resting blood pressure, and in the case of regular sauna use, significantly lower cardiovascular mortality.
• Rehydration after sweating does not require high-sodium products. Water and real food are the right move for most people most of the time.

Start With the Basics: Are You Actually Drinking Enough Water?

Before any of this can work the way it should, there is a foundational issue worth addressing. Research shows that many people start exercise already mildly dehydrated — and when we drink to thirst alone, we often replace only a fraction of what we lose. This is part of why electrolyte companies exist and why people reach for them. But in many cases, the real fix is simpler: drink more water consistently, every day, not just during workouts.

A practical starting point: aim for roughly half your body weight in ounces of water per day as a daily baseline. So if you weigh 180 pounds, that is around 90 ounces — about 11 cups — before you account for exercise or heat. On days when you train hard or spend time in a sauna, add more. ACSM guidelines suggest an additional 12 ounces for every 30 minutes of exercise as a general rule of thumb.

It is also worth noting that some everyday habits quietly work against your hydration. Caffeine is a mild diuretic — meaning it increases how much fluid your kidneys push out. A cup or two of coffee is not going to dehydrate you, but if you are consistently consuming a lot of caffeine throughout the day and not compensating with extra water, you are likely running drier than you think. Alcohol has a similar effect and is worth factoring in if that is part of your routine.

Good baseline hydration is not glamorous advice, but it is the foundation everything else in this article is built on. Intentional sweating works best when you are starting from a well-hydrated state — not digging yourself out of a deficit every time.

Important safety note: people with heart disease, kidney disease, or those taking blood thinners, diuretics, or beta-blockers should talk to their doctor before adding aggressive heat exposure to their routine. Saunas and hot water immersion place real cardiovascular demands on the body. For healthy individuals, those demands are manageable and beneficial. For people with existing conditions, they need to be managed carefully.

The Bottom Line

Your sweat glands are doing more than keeping you cool. They are pulling sodium from a reservoir in your skin that your kidneys cannot fully reach — and doing it in amounts that can make a real difference in your cardiovascular health over time.

This is not about detoxing. It is about understanding the full picture of how your body manages sodium — and giving it the tools to do that job well. Whether that means finishing your workout outside in the heat, adding a few sauna sessions each week, or simply being more intentional about when and how hard you sweat, the case for doing it just got a lot stronger.

References & Further Reading

Hoch JW, Watso JC. Can We Protect Our Hearts by Sweating Out Excess Sodium? Exercise and Sport Sciences Reviews. 2026;54(2):89–98. DOI: 10.1249/JES.0000000000000383

Babcock MC, Robinson AT, Migdal KU, et al. High salt intake augments blood pressure responses during submaximal aerobic exercise. J Am Heart Assoc. 2020;9(10):e015633.

Currie KD, Schultz MG, Millar PJ, Pescatello LS. The role of exercise blood pressure in hypertension: measurement, mechanisms, and management. Med Sci Sports Exerc. 2025;57(2):425–33.

Watso JC, Fancher IS, Gomez DH, et al. The damaging duo: obesity and excess dietary salt contribute to hypertension and cardiovascular disease. Obes Rev. 2023;24(8):e13589.

Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015;175(4):542–548.

Hussain J, Cohen M. Clinical effects of regular dry sauna bathing: a systematic review. Evid Based Complement Alternat Med. 2018;2018:1857413.

Baker LB. Sweating rate and sweat sodium concentration in athletes: a review of methodology and intra/interindividual variability. Sports Med. 2017;47(Suppl 1):111–28.

U.S. Department of Agriculture. Dietary Guidelines for Americans, 2025–2030. 10th ed. US Government Publishing Office; 2026.

Jones DW, Ferdinand KC, Taler SJ, et al. 2025 AHA/ACC guideline for the prevention, detection, evaluation and management of high blood pressure in adults. Hypertension. 2025;82(10):e212–316.

Hero Image Photo Credits: Regular exercise — especially in warmer conditions — triggers meaningful sodium loss through sweat, a benefit that goes well beyond calorie burn. Credit: Hans Reniers / Unsplash