# WOO® Fast Endurance Orange: Why Osmolality Decides How Much Energy You Absorb

> It is not the gram count that determines how well a sports drink is tolerated, but molecule size. What research shows about high-molecular-weight carbohydrates - and how WOO® Fast Endurance Orange is built.

Two sports drinks can contain exactly the same amount of carbohydrate and still feel completely different in your stomach. The difference rarely lies in the quantity - it lies in molecule size, and therefore in osmolality. If you struggle with a heavy stomach on long sessions, you usually have an osmolality problem, not a willpower problem.

## What osmolality actually does in your stomach

Osmolality describes the number of dissolved particles per kilogram of fluid. Blood plasma sits at around 290 mosmol/kg. A markedly **hypertonic** drink leaves the stomach more slowly and initially even draws water into the intestine - the exact opposite of what you need during exercise.

The decisive point is pure physics: osmotically, it is not mass that counts but particle number. A single glucose molecule counts just as much as a giant molecule made of a thousand linked glucose units. Carbohydrate density can therefore be high while osmotic pressure stays low - provided you choose the right molecular form.

## High-molecular-weight corn starch: plenty of energy, low osmotic pressure

Vist and Maughan (1995) compared solutions with identical carbohydrate concentrations but different chain lengths: the version built on long glucose polymers left the stomach measurably faster. Piehl Aulin et al. (2000) observed faster glycogen resynthesis after exhaustive exercise with high-molecular-weight starch than with conventional maltodextrin. The body of evidence is not enormous, but it is consistent on one point: at an equal carbohydrate dose, molecular form is a relevant lever for tolerance and availability.

## Why short-chain and long-chain belong together

Long chains have to be split enzymatically first; free glucose is available almost immediately. Both have their place: the fast fraction covers acute demand in the first minutes, the long-chain fraction carries the session over time and dampens the swings. This is exactly the mix of high-molecular-weight corn starch plus maltodextrin, glucose and sucrose used in **[WOO® Fast Endurance Orange](/en/shop/woo-fast-endurance-orange-can)** - according to the manufacturer, to avoid an abrupt drop in blood sugar and the classic bonk.

## What sweat takes with it

Sweating costs you more than water - above all it costs **sodium**. Per 100 g of powder it contains 500 mg of sodium and 42 mg of magnesium. Magnesium contributes to normal muscle function. Sodium, in turn, is co-responsible for glucose uptake via the SGLT1 transporter and keeps the thirst mechanism running - plain water does not do that on long sessions.

## WOO® Fast Endurance Orange in the tub: you set the dose

The 1000 g tub yields 25 servings of 40 g. Per 100 g of powder it contains 93.5 g of carbohydrate - how densely you mix is up to you. The advantage over pre-portioned sachets is dosing freedom: weaker for the calm base session, denser for hard intervals. Your gut gets used to higher carbohydrate loads step by step over weeks. Vegan, gluten- and lactose-free, with no artificial additives.

## Frequently asked questions

**What does "isotonic" mean and does my drink need to be?**
Isotonic means an osmolality similar to blood plasma. For pure fluid uptake that is favourable. If you need a lot of energy, a slightly denser mix based on long-chain carbohydrates often works better, because particle number stays low.

**How much powder per how much water?**
Dosing may be adjusted individually. Start low, test it in training and increase slowly - never debut a new concentration on race day.

**Can I drink it before the start too?**
Yes, WOO® Fast Endurance is intended before and during training.

## Sources

Vist GE & Maughan RJ (1995), Journal of Physiology - Osmolality, carbohydrate content and gastric emptying of liquids.
Piehl Aulin K et al. (2000), European Journal of Applied Physiology - Glycogen resynthesis with carbohydrates of low and high molecular mass.
Stephens FB et al. (2008), Medicine & Science in Sports & Exercise - High molecular weight glucose polymer and subsequent cycling performance.
Leiper JB (2015), Nutrition Reviews - Fate of ingested fluids: gastric emptying and intestinal absorption of beverages.

*WOO® Fast Endurance Orange in the 1000 g tub - available in our shop.*