Dextrose - Who Needs It?

If you exercise regularly and consume protein powder after your workout, you must have been advised by someone to take dextrose in addition to protein. But what is dextrose, what is it for and who needs it?

What is Dextrose?

Dextrose is a natural form of glucose, a simple sugar that the human body uses to produce energy. Dextrose contains 3.75 kilocalories of energy per gram.

Dextrose is found in honey, oatmeal, oranges and starchy foods. The human body uses glucose in a cycle with citric acid to produce adenosine triphosphate (ATP), the main energy molecule of the human body. At the same time, when ingesting an excessive amount of dextrose, it is stored in the liver and muscle as glycogen.

Dextrose is used in sports as a post-workout meal supplement (PWM) to optimize protein absorption and recover lost energy.

Dextrose in post-workout diet supplements

Dextrose is the primary source of muscle carbohydrates stored as glycogen. Higher glycogen stores also mean more energy for the muscles, which is directly linked to increased exercise capacity and later better muscle recovery capacity. The longer the workout and the harder it is, the more glycogen is consumed during this activity.

In addition to post-workout nutrition, dextrose is primarily used to make up for lost energy, which is especially important in endurance sports, since prolonged aerobic activity depletes glycogen stores, that is, energy available to the muscles. But these are extremely exhausting workouts.


However, it is wrong to think that every workout depletes glycogen stores to such an extent that they need to be supplemented significantly with special amounts of dextrose.

What does science say?

A study by Roy et al. has shown that glycogen stores are in no way exhausted by classic power trekking. The subjects in the study did full-body training consisting of 9 exercises of 3 batches at 80% of 1RM and thus exhausted only about a third of glycogen stores. At the same time, 9 batches of specific muscle deplete about 36% of the glycogen stores in that muscle.

Additionally, after performing 6 series of foot extensions at 70% 1RM until failure and without taking food after training, 75% of glycogen was restored after 6 hours. Thus, the story of the importance of dextrose intake immediately after ordinary strength training is much more a myth than evidence-based reality.

At the same time, the function of dextrose in power sports is still questionable. Specifically, bodybuilding circles have believed for decades that dextrose intake after strength training improves protein synthesis, but this thesis still lacks scientific evidence.

Kerksick and Leutholtz, in their review of dietary supplements in the context of training, have shown that protein intake alone leads to protein balance and synthesis in a very similar measure to that of a combination of amino acids and carbohydrates. Additionally, upon their conclusion, a small amount of amino acids after strength training promotes similar changes in protein synthesis and balance with and without additional carbohydrates.

Koopman et al. divided the subjects into three groups: ingesting 0, 0.15, or 0.6 g carbohydrates per kg body weight with 25g whey protein after strength training. Total body degradation, synthesis and rate of protein oxidation as well as total protein balance did not differ between subjects. According to their conclusions, carbohydrate intake in the recovery phase does not promote protein synthesis.

Lastly, both Staples et al. did a test between two groups: one after strength training received 25 g of whey protein and the other 25 g of whey protein in combination with 50 g of maltodextrin. According to the conclusion, there was no difference between the groups in protein synthesis, as well as in the prevention of protein degradation.

Therefore, from all of the above it can be concluded that the addition of dextrose to proteins in PWM has no justification either in terms of preventing catabolism or as an aid to protein synthesis, and glycogen stores are virtually impossible to consume by trekking power, so this reason for dextrose intake is also unjustified.


Dextrose is justified for use only after extremely strenuous workouts and endurance sports, when really all the glycogen stores have been consumed, and this is extremely rare and the athlete himself is then in a state of complete weakness and muscle exhaustion.