Touch of caffeine makes pre-workout shake more effective


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.

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.

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.

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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.

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It’s worth mentioning that not all subjects reacted positively to caffeine. For one of them, the addition of caffeine had the reverse effect.

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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.

Gastrointestinal function during exercise: comparison of water, sports drink, and sports drink with caffeine.

Van Nieuwenhoven MA, Brummer RM, Brouns F.

Source

Department of Gastroenterology, University Hospital, Maastricht, 6202 AZ Maastricht, The Netherlands. m.vannieuwenhoven@hb.unimaas.nl

Abstract

Caffeine is suspected to affect gastrointestinal function. We therefore investigated whether supplementation of a carbohydrate-electrolyte solution (CES) sports drink with 150 mg/l caffeine leads to alterations in gastrointestinal variables compared with a normal CES and water using a standardized rest-exercise-rest protocol. Ten well-trained subjects underwent a rest-cycling-rest protocol three times. Esophageal motility, gastroesophageal reflux, and intragastric pH were measured by use of a transnasal catheter. Orocecal transit time was measured using breath-H(2) measurements. A sugar absorption test was applied to determine intestinal permeability and glucose absorption. Gastric emptying was measured via the (13)C-acetate breath test. In the postexercise episode, midesophageal pressure was significantly lower in the CES + caffeine trial compared with the water trial (P = 0.017). There were no significant differences between the three drinks for gastric pH and reflux during the preexercise, the cycling, and the postexercise episode, respectively. Gastric emptying, orocecal transit time, and intestinal permeability showed no significant differences between the three trials. However, glucose absorption was significantly increased in the CES + caffeine trial compared with the CES trial (P = 0.017). No significant differences in gastroesophageal reflux, gastric pH, or gastrointestinal transit could be observed between the CES, the CES + caffeine, and the water trials. However, intestinal glucose uptake was increased in the CES + caffeine trial.

PMID: 10956354 [PubMed – indexed for MEDLINE]

Source: http://www.ncbi.nlm.nih.gov/pubmed/10956354

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