The Science
Why Rein Works Differently
Most electrolyte products are built for the general fitness market — athletes who don't have to step on a scale. Rein Hydration was engineered from the ground up for one specific challenge: how do you rehydrate a jockey efficiently, without adding unnecessary water weight?
The answer comes down to one scientific concept: osmolality.
Why Drink Concentration (Osmolality) Matters
The concentration of a drink affects how quickly and comfortably your body can absorb it. This is measured by something called osmolality, which simply means how many particles — like electrolytes and carbohydrates — are dissolved in the liquid.
Your blood has its own natural concentration. The body naturally tries to keep particle concentration balanced on both sides of a barrier, such as the blood vessel wall. The particles themselves do not always move easily, so water is what shifts to help even things out.
Drinks that are much more concentrated than blood are called hypertonic. These can sit heavier in the stomach because the body may need to pull water into the gut first to dilute them before fluid can move efficiently into circulation.
Rein is designed to be slightly less concentrated than blood, or hypotonic. That means the fluid is positioned to move more easily from the gut into the bloodstream. For jockeys, this matters because hydration needs to be fast, light, and effective — especially when there is limited time to drink before or between races.
Your blood sits at roughly 285–295 mOsm/kg. The concentration of what you drink determines how fast it's absorbed.
Rein is formulated to be hypotonic. With 1 scoop in 8 oz of water, the solution is rapidly absorbed — delivering electrolytes where you need them, faster, with a smaller total fluid volume.
Electrolyte Profile — Per Serving
Primary electrolyte lost in sweat. Critical for fluid balance. Sourced from Redmond Ancient Sea Salt and Sodium Citrate, which buffers muscle acidity during exertion.
Works with sodium to regulate osmotic pressure and fluid distribution inside and outside cells. Also supports proper nerve signal transmission.
Primary intracellular electrolyte. Essential for muscle contraction, heart function, and preventing cramping. Must be replenished alongside sodium.
As Methylcobalamin — the most bioavailable form. Supports cellular energy metabolism without artificial spikes or crashes. Ideal for athletes managing weight and performance.
Ancient Utah Sea Salt
Redmond Real Salt — mined in Utah
Sourced from an ancient seabed left over 200 million years ago — before industrial pollution existed. This unrefined salt naturally contains over 60 trace minerals largely stripped from commercially processed salts. These trace minerals work synergistically with the primary electrolytes for broader cellular support.
Clean Formula Commitment
This page is for general information purposes only and does not replace advice from a qualified medical professional or sports dietitian.