Do you need carbohydrates during training?

Only if the effort lasts more than an hour continuously. There, sports nutrition recommendations set 30-60 g per hour, and up to 90 g in efforts of more than two and a half hours combining glucose and fructose. In a one-hour gym session you do not need them: glycogen does not run out.

What is the difference between maltodextrin, dextrose and amylopectin?

Less than the price suggests. Dextrose is pure glucose, maltodextrin is short glucose chains, and amylopectin or cyclodextrin are modified starches sold for faster gastric emptying. For most people maltodextrin covers the use at a fraction of the price; the difference that is proven is mixing two different sources, not switching brands.

Why do carbohydrates have no score on this site?

Because there is no effective dose of "carbohydrate" to cite the way there is for creatine: what exists is an amount per hour of exercise, which depends on how long you go and what your gut tolerates. So this category is compared by price per kilo, which is exactly the question of whoever buys it.

Do carbohydrate powders make you fat?

They add calories like any food, and since you drink them they are not very filling. Within a long session they do a job; outside it, they are liquid calories that are easy not to count. If the goal is losing fat, it is the first tub to go from the cupboard.

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Carbohydrates · Strong evidence

What carbohydrate powders are for and when you need them

The short answer. A carbohydrate powder is sugar that is easy to drink. Its evidence-backed use is long training: beyond an hour of continuous effort, taking in carbohydrate during the session sustains performance, and the limit is set by the gut, not the brand on the tub. Between maltodextrin, dextrose and the fashionable pricey versions the practical differences are small, and the price per kilo between them is not.

Several meta-analyses or position stands from scientific societies agree that there is an effect. No figure on this page is attributed to a specific product: the effect belongs to the ingredient and every number carries its source next to it.

01 What it does and how much

Each row is a measured effect, with the figure the study gives and the source number. Where the evidence gives no figure, the column says so instead of making up a percentage.

Effects of carbohydrate powder with their source
Effect	How much	Detail
Efforts of 1 to 2.5 hours	30 to 60 g per hour	It is the recommended range to sustain performance in continuous work. Below an hour of effort, you need nothing. [1]
Efforts over 2.5 hours	up to 90 g per hour	Only by combining two sources (glucose plus fructose), because they use different transporters in the gut. With a single source the ceiling stays at about 60 g. [1]
Glycogen refuelling after training	1.0 to 1.2 g/kg/hour	It only really matters if you compete or train again within eight hours. With 24 hours ahead, eating normally is enough. [1]
One-hour gym session	not needed	Glycogen does not run out in a weights session. Drinking carbohydrate there adds calories, not performance. [1]

02 How to take it

Dose. 30 to 60 g per hour of long continuous effort. Outside that, the day’s food.
When. During the session, or right after if you have to go again within a few hours.
How long before you notice it. It is an acute effect, within the same session.

Details that change the result

Train your gut: 60 g per hour is not tolerated first time. Build up gradually in training, never on race day.
Maltodextrin is the cheap option and does the job. Amylopectin and cyclodextrin promise faster gastric emptying and cost several times more.
Mixing glucose with fructose is the only thing that raises the ceiling above 60 g per hour, and that is well established.
Two hours on the bike with nothing to drink, the cheap tub does infinitely more than the expensive one you did not buy.

03 When it makes sense and when it does not

Worth it if

Cycling, long runs, triathlon or any continuous effort over an hour.
Two sessions on the same day with few hours between them.
Team sports with long matches and little room to eat.

Not worth it if

A one-hour weights session: there is no glycogen to replace mid-session.
When cutting, unless the training is genuinely long.
Paying three times more for cyclodextrin when maltodextrin covers your case.

04 Sources

Every figure above comes from here. They are position stands from scientific societies, meta-analyses and peer-reviewed reviews: if a claim cannot hang from one of these lines, it is not on the page. References are cited in their original form.

Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Med Sci Sports Exerc. 2016;48(3):543-568. 30-60 g/h en esfuerzos de 1-2,5 h y hasta 90 g/h con fuentes multiples por encima de 2,5 h. doi:10.1249/MSS.0000000000000852
Kerksick CM et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. Recarga de glucogeno a 1,0-1,2 g/kg/hora cuando hay que repetir esfuerzo en menos de 8 horas. doi:10.1186/s12970-018-0242-y

This is not medical advice. It is what some studies say about an ingredient, not a protocol for you. With an illness, medication or pregnancy involved, the decision belongs to a healthcare professional who knows you.

Questions about carbohydrate powder

Answered with the data on this page

Do you need carbohydrates during training?: Only if the effort lasts more than an hour continuously. There, sports nutrition recommendations set 30-60 g per hour, and up to 90 g in efforts of more than two and a half hours combining glucose and fructose. In a one-hour gym session you do not need them: glycogen does not run out.
What is the difference between maltodextrin, dextrose and amylopectin?: Less than the price suggests. Dextrose is pure glucose, maltodextrin is short glucose chains, and amylopectin or cyclodextrin are modified starches sold for faster gastric emptying. For most people maltodextrin covers the use at a fraction of the price; the difference that is proven is mixing two different sources, not switching brands.
Why do carbohydrates have no score on this site?: Because there is no effective dose of "carbohydrate" to cite the way there is for creatine: what exists is an amount per hour of exercise, which depends on how long you go and what your gut tolerates. So this category is compared by price per kilo, which is exactly the question of whoever buys it.
Do carbohydrate powders make you fat?: They add calories like any food, and since you drink them they are not very filling. Within a long session they do a job; outside it, they are liquid calories that are easy not to count. If the goal is losing fat, it is the first tub to go from the cupboard.

And now, which to buy

Prices, kept apart from the evidence

This page explains what carbohydrate powder does and deliberately names no brand. The comparison is the other half: 113 products from 13 stores from €3.02 per kg, sorted by price and by how verifiable their certification is.

See the carbohydrates comparison

Other guides

What each supplement does, with its sources