Research Articles

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Sodium: A Deep Dive on Sweat and Sodium
Almost every athlete can tell you their bodyweight, their max lifts and run times. Almost none can tell you how their sweat rate and how much sodium they lose in a session. They are numbers  that can have a ten-fold variation between people, and they are numbers nobody measures. How sweat is actually made Sweat glands work in two stages. The secretory coil, deep in the skin, produces a precursor fluid that is the same as blood plasma. That fluid then travels up the duct toward the skin surface, and... Read more...
Buffers - Bicarb, citrate, malate, beta-alanine
If your sport involves repeated maximal efforts lasting between thirty seconds and ten minutes, buffering is an intervention that can have a big impact on performance. It's also the one most often skipped, because of potential adverse effects from the main supplement that helps. The problem being solved is acidosis. Sustained high-intensity work produces hydrogen ions faster than you can clear them. Falling muscle pH interferes with the enzymes that drive glycolysis and with calcium handling in your muscles. The result is the specific, unmistakable failure of a muscle that... Read more...
All about caffeine
Caffeine is probably  the most reliable ergogenic aid available, and can really improve athletic performance. The primary mechanism is adenosine antagonism. Adenosine accumulates through the day and through a session, binding to central receptors and producing the sensation of fatigue. Caffeine occupies those receptors without activating them. Perceived effort drops, and you can work harder for the same energy cost. Secondary effects of caffeine on calcium handling in muscle and on motor units contribute, but the central effect does most of the work. How strong is the evidence? Grgic and... Read more...
Creatine and what it actually does
Creatine is the most studied supplement in sport and still widely misunderstood. It isn't a stimulant or a steroid, and it doesn't build muscle directly. It buys you a few more seconds of maximal output, and everything else builds off that. The mechanism uses the phosphocreatine system. ATP is the energy currency your muscle spends, but you only store a few seconds' worth. When you use ATP, it loses a phosphate group.   Phosphocreatine is also stored in muscle and it donates a phosphate to regenerate ATP almost instantly, which is... Read more...
Magnesium: its role in performance
Magnesium doesn't get the attention sodium does. It's not what you taste in sweat, and it's not the electrolyte people ask about when they cramp mid-session. But it's a cofactor in more than 300 enzyme systems — energy production, glycolysis, protein synthesis, muscle and nerve function, blood glucose control — and unlike sodium, many people are already running short of it before they've done a single rep [1]. That combination — high physiological demand and common deficiency— is why magnesium is worth understanding properly. Sweat losses: real, but not the... Read more...
Carbohydrate Isn't Just Fuel — It's How Water Gets In
Most people think of carbohydrates in a drink as calories. However they are doing something in addition to that: they are driving fluid across your intestinal wall. Water absorption in the small intestine is passive. It follows solute. The main mechanism is SGLT1, a sodium-glucose cotransporter in the brush border membrane that moves two sodium ions across for every glucose molecule.¹ Sodium and glucose move into you body, an osmotic gradient is created, and water follows. This is the physiology that oral rehydration therapy products such as Dioralyte are built... Read more...
What Dehydration Actually Costs You
"Two percent dehydration and performance falls off a cliff" is repeated so often it's stopped meaning anything. The literature is more specific than that, and more useful. Let’s start with the mechanism: losing body water reduces plasma volume. Reduced plasma volume means lower stroke volume (the amount of blood your heart pumps with each beat), so heart rate rises to maintain cardiac output. At the same time, skin blood flow — your main way of dumping heat — has to compete with muscle for a smaller circulating volume. Core temperature... Read more...
Why Water Alone Won't Rehydrate You
Drink a litre of water after a hard session and a good portion of it never reaches the tissue that needs it. It goes to your bladder. The problem is osmolality. Sweat is hypotonic — it contains less sodium than the plasma it comes from. So as you sweat, you lose proportionally more water than sodium and plasma becomes more concentrated-osmolality climbs. That rise is what drives thirst and antidiuretic hormone release, and it's the signal that tells your kidneys to hold onto fluid.1 So you drink plain water. Plasma... Read more...