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Gut Check (How hydration works inside)

Gut Check (How hydration works inside)

Gut Check (How hydration works inside)

As we covered in our post Hydration is Power, to maximise and sustain power you need to stay hydrated. As body-water drops, so does aerobic power; by the time you’re thirsty you’re already about 2% below optimal body water, which can result in an 11% reduction in power output.

To summarise, as endurance athletes, our bodies produce power through aerobic metabolism. Aerobic metabolism requires oxygen-rich blood to flow to the muscles. As body-water drops (due to perspiration and respiration), blood “thickens”, which reduces heart-stroke volume. Reduced heart-stroke volume means less blood-carrying oxygen makes it to your muscles, and power drops.

On top of this, when we’re working-out at a high intensity or working-out when it’s hot, we can lose body water faster than we can replace it. So re-hydrating as rapidly as possible is critical to maintain power output.

This brings into focus three pro tips:
1) Start your workout fully hydrated (see Performance Begins with Pee),
2) Don’t wait until you’re thirsty before you start drinking, and
3) Drink Osmo Active Hydration during your workout, because it’s been developed to be the fastest way to replace body-water orally—and speed is key.

Okay, so we’ve established that speed of rehydration is important. Let’s dive a little deeper.


How is Osmo so fast at replacing body-water?

In totally non-scientific language, you need to drink something with the right stuff in it, but not too much stuff. Let’s talk about our guts to find out why.

Fluid is absorbed in the intestine either passively (via osmosis – the movement of fluid from lower concentration to higher concentration), or “actively”, using what scientists call an “Active Co-transport” system (This is where the “active” in Active Hydration gets its name, BTW).


What’s active co-transport?

Meet Dr Crane. In 1960, Dr. Robert Crane presented his discovery of the sodium-glucose co-transport system. Later, The Lancet called Crane’s discovery: “…the most important medical advance this century.”   In plain language, when glucose and sodium are present in the small intestine, water is drawn into the bloodstream at a much faster rate.

Crane’s discovery of co-transport led directly to the development of oral rehydration therapy—which has saved the lives of millions of people suffering from dehydration in underdeveloped countries. Crane’s discovery also paved the way for Osmo Active Hydration.

Our team at Osmo has since studied, tested and perfected the science of oral rehydration, honing the ratio of sodium (and other electrolytes), glucose and the other natural and organic ingredients to maximize the rate of fluid absorption, ensure electrolyte replacement, and deliver a light taste that is not boggy and weird.


What You Can Do

After we swallow whatever we drink, it passes into the gastrointestinal tract (stomach and intestines). It then enters the vascular system as blood plasma, goes to interstitial spaces (the area between cells), and is transported to every cell. Our stomach and small intestine are critical organs when it comes to hydration. Let’s talk about the stomach first. In layman’s terms, it’s primary job is to prepare the fluid we’ve consumed to be absorbed in the intestines.

To do this, the stomach ensures that the liquid consumed has a lower osmolality than our blood. Osmolality is a measure of how much solid is dissolved in the fluid. In plain language, how much “stuff” is dissolved in the fluid. The fluid needs to be equal to or lower in osmolality than blood or the intestine can’t absorb it. So, if there is too much “stuff” dissolved in the solution, the liquid will be held in the stomach while body water is drawn from the blood plasma into the stomach to dilute it.



This is called “reverse flux” and it’s bad because it removes body water from circulation, effectively dehydrating you. Yes, it actually dehydrates you to drink the wrong fluid. Moreover, because reverse flux takes time, it also delays “gastric emptying” slowing rehydration. Finally, since the fluid is being held in your stomach, it can lead to a bloating and “gut rot.”

So, it’s critical to drink a solution that’s has a lower osmolality than blood. Osmo Active Hydration does. Almost all other hydration mixes have a higher osmolality than blood. Put another way, in order to re-hydrate quickly and properly, you can’t drink fluid that has “too much stuff”. Note: Generally, the higher the calorie count, the higher the concentration. Look for future posts to explain, but for now just remember that you should go with “food in your pocket, and hydration in your bottle”. Never use liquid forms of calories.

But that leaves the question…


What is the right stuff?

Into the intestines we go….

After leaving the stomach, fluid is absorbed mostly in the early segments of the small intestine, the duodenum and the jejunum. About 80% of all fluid you drink is absorbed in the small intestine absorbs.

So what can you do to stay properly hydrated and avoid dehydration? We know we sound like a broken record, but we hope you’re listening:
1. Rehydrate when you wake up.  We lose body water while we’re sleeping, so drinking 16 ounces of water during the first hour of waking will help top-up your body water.

Note: Check out “Performance Begins with Pee” to learn about processes and tools we provide to help you monitor your hydration status.

2. Start your workout hydrated. Drink 20 ounces of Osmo Active Hydration over the 30 minutes preceding your workout.

3. During your workout, start drinking immediately and drink small sips every 10 minutes or so.  Most people, under most conditions, should drink 20-25 ounces of Osmo Active Hydration per hour of exercise (roughly one small or large water bottle).

Lighter athletes or athletes exercising in cool weather conditions may only require 16-18 ounces an hour. Larger athletes or athletes exercising under hot and humid conditions may require more than 30 ounces an hour.

4.In situations where you will be losing body water faster than you can replace it (exercising in hot weather, or exercising at high intensity, or for long duration) drink Osmo PreLoad hydration to hyper-hydrate (go above normal body water. When you drink PreLoad as recommended, you will end up with between 8-11% more blood plasma than normal.)

Hopefully this post has given you a new appreciation of your gut, and a better idea of why it’s critical to drink the right stuff to maintain hydration. Because staying properly hydrated is critical to maximize power and endurance.

Live long and perspire.