The primary reason for carbohydrate supplementation is either to maintain blood glucose levels during training, or to replenish glycogen levels rapidly after training, to recover as quickly as possible.
As glycogen depletion is not a factor in the training of most recreational exercisers (and most resistance training athletes) the former is not an issue, and the latter is handled adequately by simply consuming carbohydrates in the meals between training sessions. In short, eating normally with an adequate carbohydrate intake will ensure most individuals have enough stored glycogen to compensate for the activity at hand, and will replenish that which is lost during a training session before the next one.
With that said, for those looking to improve performance over prolonged periods or looking to train intensely more than once per day – carbohydrate powders may be a useful tool. Ingestion of 30-60g of carbohydrates per hour can increase various markers of exercise performance in exercise lasting up to 2 hours, with dextrose and maltodextrin being the cheapest and yet most well researched forms of carbohydrate capable of having this effect. By combining the two with fructose (which uses a different transporter protein to exit the small intestine and can preferentially replenish liver glycogen, therefore freeing consumed glucose to replenish muscle glycogen and maintain blood glucose), it’s possible to increase the 1g of carbohydrate per minute (60 per hour) top level to 1.2-1.75g per minute which seems to be useful for exercise lasting 2 hours or more. Large amounts of fructose consumed at once can lead to gastric upset and should therefore be avoided. Generally, a 1:1:1 ratio, or ratio which emphasises dextrose and/or maltodextrin over fructose is used, with a 1:1:1 ratio having been shown to improve cycling performance over 2 hours incrementally between doses of 10g per hour and 78g per hour before athletes saw diminishing returns.
Two popular, highly priced forms of supplemental carbohydrate are Vitargo and Waxy Maize Starch. The latter has not been shown to be more beneficial than dextrose in that it does not increase blood glucose faster or more efficiently (despite costing a great deal more), but the former does indeed appear to be capable of passing digestion faster owing to its unique structure. It therefore may improve performance in the second workout of a 2-per-day routine more than cheaper carbohydrate forms like maltodextrin or dextrose.
Ultimately the difference is minor but very real, and a cost:benefit analysis should be considered before opting for either a maltodextrin/dextrose/fructose mix or Vitargo alone. Finally, if you are considering using carbohydrate beverages simply to increase your overall calorie and carbohydrate intake throughout the day without needing to consume additional solid foods, any carbohydrate would suffice, though an oat flour would contain more micronutrients and fibre than other supplemental carbohydrates, and that may or may not be a meaningful factor depending on the rest of an overall diet. Of course, when possible, carbohydrates should be added to smoothies using fruit or other foods and a blender.