Dextrose is the basic energy source of animal metabolism. As a nutrient, its energy value in the human organism is 17kJ/g. It is in addition the main energetic substrate the brain uses.

Dextrose is quickly absorbed from the small intestine. It produces a rapid glycemic response and provides an immediate source of energy for the organs, muscles and brain. Alternatively, it can be stored as glycogen in the liver or in muscles, so forming the body’s energy reserves.

Energy management

Carbohydrates should contribute to 55 percent of the daily energy intake for human beings, which means that for a daily requirement of 2.000 calories, the consumption of around 300 g carbohydrates is recommended. Dextrose can contribute partly to this calorie intake.

It is generally accepted that carbohydrate feeding during exercise can improve endurance capacity (time to exhaustion) and exercise performance during prolonged exercise (>2h). There are several mechanisms by which carbohydrate feeding during exercise can improve performance. These include maintaining blood glucose and high levels of carbohydrate oxidation, sparing endogenous glycogen, synthesizing glycogen.

Carbohydrates can be divided into two categories according to the rate at which they are oxidized (used as energetic substrate by the muscle cells). Dextrose is oxidized at relatively high rates (1g/min) compared to other monosaccharides like fructose and galactose (0.6 g/min), which makes dextrose an ideal carbohydrate, as performance improvements likely to be related to maintenance of high rates of carbohydrate oxidation and the prevention of hypoglycemia.

This last statement is supported by several studies, which show that ingestion of dextrose-electrolyte drinks can improve exercise performance even when the amount of added dextrose is small.