The End of Electrolytes? Just Eat Carbohydrates for Hydration…

Thomas argues that plain water during exercise is counterproductive because it reduces plasma osmolality, suppresses AVP, and increases urine loss. A hypotonic solution—more dilute than blood but not pure water—strikes the optimal balance. His chosen ratio (1000 mg sodium, 200 mg potassium, 60 mg magnesium) is intentionally skewed toward sodium for better water retention in the extracellular space and for muscle fullness. He notes that when training for fat loss, any carbohydrate intake, even small, can raise insulin and blunt lipolysis, so a zero-sugar electrolyte is the ideal tool. The product contains no sugar and uses a higher sodium-to-potassium ratio compared to many sports drinks, which he finds gives a better muscle pump.

Drawing on a military committee study, DeLauer highlights that soldiers who lost 3% body weight from dehydration saw exponential performance drops. Sodium alone helped, but adding a 5-10% carbohydrate solution to their fluids gave an extra hydration edge during extreme exertion. He explains that the SGLT1 transporter is the reason: having both sodium and glucose available in the gut lumen begins a co-transport cascade, and water piggybacks along. However, he stresses that this is a marginal gain—not a license to chug Gatorade. The effect is saturated at a very low carbohydrate dose, and for everyday fitness enthusiasts, zero-sugar electrolytes suffice. He mentions coconut water (approx. 6-7g carbs per cup) as a natural implementation of this principle.

DeLauer identifies watermelon as his personal favorite carb source for hydration. He breaks down its composition: 92% water, nearly 200 mg potassium per cup, and a modest carb load consisting of glucose and fructose. He calls citrulline, abundant in watermelon, a 'trigger for vasodilation,' allowing water to 'flow through and actually hydrate the tissue.' He suggests it is especially useful when paired with a quality electrolyte supplement, because you then get extra sodium to hold the water extracellularly while the watermelon's potassium and citrulline improve intracellular hydration and delivery. He sees this as a superior food-based approach to simply drinking sugar-laden sports drinks.

DeLauer reviews a study from the International Journal of Health Sciences that compared coconut water to regular water during exercise. While the hydration advantage was modestly significant, coconut water did improve performance and retention. He notes that with 6-700 mg of potassium per cup, it draws a lot of water into cells, and the natural sodium content helps retain it. The 6-7 g of carbs per cup happens to be exactly the amount shown by the military study to optimally boost hydration via SGLT1, making coconut water an elegantly packaged option from nature. He advises against brands that add sugar, as that would skew it hypertonic and possibly impair hydration.

Thomas recalls his father's generation giving milk to athletes after tennis matches. The cited study compared milk against multiple beverages; milk tied with an oral rehydration solution and beat Powerade and water. He explains that the lactose provides the carb trigger for SGLT1, the mineral profile mimics a light electrolyte solution, and the proteins add a unique angle. He advises, however, that milk is not for everyone intra-workout due to digestion. For him, it would be a 'digestive nightmare' while training, but later in the day it could contribute to better overall hydration status. He sees this as an underutilized, whole-food hydration tool.

DeLauer emphasizes that chia seeds hold 10-12 times their weight in water. By gelling them in an electrolyte solution, he creates time-released hydration that he uses for ultra-training. He contrasts this with the typical pattern of chugging large amounts of water sporadically, which leads to peaks and troughs in hydration and suppression of AVP. This protocol allows him to stay consistently hydrated over 20+ miles in warm weather. He advises it is not for everyday uniform hydration but a specialized tool for specific endurance demands.

DeLauer points out that ancestral humans likely didn't have unlimited pure water, so our bodies are adapted to mineral-rich hydration. He cites both a Journal of Applied Physiology paper and the sports medicine meta-analysis. He notes bodybuilders exploit this AVP suppression to cut water before contests by drinking pure water while sodium-depleting. For the average person exercising, this means water alone can be counterproductive. He recommends always pairing water with some electrolytes—even a pinch of salt—to maintain AVP tone and keep fluid where it belongs.

DeLauer explains that while glycogen stored in muscle brings water volume, direct carbohydrate ingestion's role in hydration is often misunderstood. He cites a military research study that found a 5–10% carbohydrate solution boosted hydration a bit more than electrolytes alone during intense exertion. The key is the SGLT1 transporter: a sodium-gated channel that allows glucose to enter cells, and water follows passively by osmotic pull. This means you don't need massive carb loads; he notes that coconut water with 6–7 g of carbs per cup is already enough. The practical takeaway is that if you already consume electrolytes, adding a smidge of carbs can offer a marginal benefit, but it's not necessary—and for those training in a fasted or fat-loss state, the insulin spike from even a few grams of carbs might be undesirable.

The meta-analysis compared hypertonic (more concentrated than plasma), isotonic (similar concentration), hypotonic (less concentrated), and plain water. Hypotonic solutions led the pack in hydration efficacy. The mechanism, DeLauer explains, involves plasma osmolality: drinking plain water during exercise lowers plasma osmolality, which suppresses arginine vasopressin (AVP). AVP is the hormone that signals the kidneys to retain fluid; when suppressed, urine output increases, potentially accelerating dehydration. A hypotonic solution with some electrolytes keeps AVP in a range that retains water without causing the sluggish absorption that can happen with denser isotonic/hypertonic fluids. He emphasizes this as a reason to use a light electrolyte supplement like his preferred Element, which provides sodium, potassium, and magnesium without sugar.

DeLauer recounts his father telling him about athletes drinking milk after exertion in earlier decades. The study compared water, skim milk, whole milk, a diarrhea rehydration formula, orange juice, regular soda, diet soda, and Powerade. Milk and the oral rehydration solution tied for best hydration score. He attributes this to three factors: (1) the lactose in milk activates SGLT1, pulling in sodium, glucose, and water; (2) milk's mineral profile includes calcium, sodium, and potassium which contribute to fluid balance; (3) emerging research suggests bioactive peptides from whey and casein may directly assist muscle hydration. However, he cautions that drinking milk during intense workouts may cause digestive distress for some, so he recommends it as a post-exercise or throughout-the-day hydrator.

DeLauer explains that once chia seeds are soaked, they form a mucilaginous gel that sits in the stomach and slowly releases water and any dissolved electrolytes over time. This prevents both the sloshing sensation and the risk of AVP suppression from boluses of plain water. He personally uses this technique by soaking chia seeds in his Element electrolyte solution, creating a continuous drip of mineralized water during long training runs (>20 miles) in warm conditions. He cautions it's not necessarily for everyday hydration but is a powerful tool for specific endurance scenarios.

DeLauer cites a study in the Journal of Applied Physiology, explaining that large boluses of plain water suppress AVP. When AVP is low, the kidneys don't reclaim water efficiently, and urine output increases. This creates a net loss over time. He mentions that bodybuilders use this principle before competitions: they drink large amounts of water while cutting sodium to flush out subcutaneous water. However, for exercisers, this leads to a decline in plasma volume, muscle fullness, and performance, especially once body weight drops 3% from water loss—at which point work capacity plummets exponentially. The solution is to always pair water with minerals (sodium, potassium) to maintain osmolality and AVP tone.