Carbohydrate powders are supplemental carbohydrates. They were the first sports supplements produced, thanks to Gatorade – a carbohydrate beverage initially formulated for the American football team, the Florida Gators.
Carbohydrate powders come in a multitude of forms, most notably dextrose (pure glucose), maltodextrin (a rapidly digested polysaccharide produced by partially hydrolysing longer starches derived from corn or wheat), fructose, Waxy Maize starch (A starch comprising primarily of amylopectin, the highly-branched form of starch which is easy to digest) or the branded carbohydrate form, Vitargo. Additionally, oat flour can be marketed as a carbohydrate supplement to be added to whey protein, but whether this is a supplement or a food comes mostly down to your perspectives on the definition of both words.
There are four primary reasons for carbohydrate supplementation, namely:
The first three aims are typically catered for by sports drinks which may be hypotonic, isotonic or hypertonic. Tonicity is the measure of relative concentration of a solution, and when talking in terms of sports drinks the concentration against which they are measured is an approximate concentration of carbohydrate and sodium in your blood.
As you have learned throughout this course, blood levels of glucose, sodium and potassium are kept relatively even (with potassium being stored almost exclusively in the intracellular water compartment). This means that the sodium concentration of the liquid exiting the stomach alters the sodium concentration of the blood, and depending on the circumstances this could be an issue. Here are the properties of each drink, and the times that they may be useful.
These generally contain less than 4g of carbohydrate per 100ml (sometimes zero carbohydrates) and less than 50mg of sodium. This concentration is lower than that in your blood, and therefore not all that useful for replenishing large amounts of lost water and sodium (lost through sweat) nor large amounts of carbohydrates.
With that said, these drinks often taste pleasant which promotes voluntary drinking, and the small amount of useful ingredients can give some small boost to daily intake. These drinks are most effective when used simply for refreshment during exercise lasting roughly one hour or less. Typical resistance trainees need not look further if they are going to drink anything at all other than plain water, and the same can be said for typical gym goers who engage in exercise for an hour or less for the purpose of improving general fitness.
These contain 6-8g of carbohydrate per 100ml and 46-51mg of sodium. This is roughly the same concentration as that in your blood and for that reason these are the most popular sports drinks amongst athletes. By consuming an isotonic drink you will replenish electrolytes and water lost through sweat, therefore avoiding the dilution of serum sodium and the associated negative consequences associated. The carbohydrate content of these drinks is also relatively high meaning that they can help to maintain endurance performance for longer – with sports drinks regularly appearing to help improve performance, reduce fatigue and extend time to exhaustion in exercise lasting over an hour.
These drinks (or gels) generally contain over 10g of carbohydrates per 100ml and are used primarily for the purpose of replenishing depleted glycogen. Typically, they will contain no electrolytes. The high concentration of carbohydrates can slow gastric emptying and therefore delay rehydration and so these should be avoided after training in those who are particularly dehydrated. Consuming a high-carbohydrate drink after a depleting performance will increase subsequent performance significantly if that performance is to be undertaken within a short period of time, but there is no additional benefit to high-carbohydrate intakes from supplements after training if an individual is not training again for 24 hours. By this time interval, normal carbohydrate consumption from food will have replenished what was lost in usual circumstances (ultra-endurance running and other exceptional activities should be taken on an individual basis).
An important thing to note is that each of the above drinks contain calories and those calories matter. Someone looking to lose fat that drinks a high-carbohydrate sports drink during exercise could potentially ‘override’ the calorie expenditure of the session itself. Sports drinks should be reserved exclusively for individuals looking to improve performance rather than recreational exercisers looking to improve their health through normal amounts of training. However, there is an argument that electrolyte supplementation may be of benefit to those who sweat particularly profusely.