From Ergo Log
If you make sure your muscle cells get enough amino acids before, during or after your workout, you’ll build up strength and muscle mass faster. You can probably make your pre- and post-workout nutrition even more effective if you add a small amount of caffeine. We deduce this from a Dutch study published almost fifteen years ago in the Journal of Applied Physiology.
The study we’re talking about here was funded by Novartis. The idea behind the study was to find a solution to a problem that many athletes who use energy drinks complain about. During training sessions or competitions they sometimes find it difficult to keep the stuff down. The researchers wanted to find out whether the body reacts better during exertion to a sports drink with caffeine added.
To cut a long story short: it’s just as difficult to keep down a sports drink with caffeine added as one without. But during exertion you absorb the glucose in an energy drink – and therefore probably also the amino acids and peptides in a shake – better when they are combined with caffeine.
On three different occasions the researchers gave ten well-trained men aged between 18 and 25 either water, or a sports drink containing electrolytes and 7 g carbohydrates per 100 ml [CES], or a sports drink containing electrolytes, carbs and 15 mg caffeine per 100 ml [CES+Caf]. After the subjects had drunk the water or sports drink, the researchers got them to cycle hard.
The carbohydrates the researchers added to the drink were 3-O-D-methyl-m-glucose [3-OMG] and rhamnose. The gut cells don’t automatically absorb 3-O-D-methyl-glucose. To do so they need energy, in the form of ATP molecules. The ATP molecules enable transport proteins in the gut cells to function.
This is the case not only for 3-O-D-methyl-m-glucose, but also for glucose, amino acids and peptides.
To absorb rhamnose, however, the gut cells do not require any energy: it’s absorbed passively.
In the subjects’ urine the ratio of 3-O-D-methyl-m-glucose to rhamnose altered as a result of the presence of caffeine, the researchers discovered. The relative amount of 3-O-D-methyl-m-glucose increased. That means that caffeine boosts the uptake of glucose during physical exertion.
It’s worth mentioning that not all subjects reacted positively to caffeine. For one of them, the addition of caffeine had the reverse effect.
There’s a pretty good chance that your pre-workout shakes will be more effective if you take a bit of caffeine at the same time. A cup of coffee should provide enough caffeine to do this.
J Appl Physiol (1985). 2000 Sep;89(3):1079-85.