Coffee as a Pre-Workout Boost: Right or Wrong?

There's a good reason why caffeine is the most popular drug in the world. Not only does it give you a mental lift, there are also plenty of studies to show that it can improve exercise performance.

However, don't make the mistake of assuming that the effects of caffeine always extend to caffeinated drinks such as coffee.

In fact, there is evidence to show that coffee doesn't give you the same pre-workout performance boost as caffeine.

In a study carried out at the University of Guelph, researchers attempted to distinguish between the effects of caffeine taken as a capsule or in the form of coffee [1].

For the study, nine subjects (actively training endurance runners) completed five trials in which they ran "to voluntary exhaustion" on a treadmill.

Roughly 60 minutes before each trial, they were given one of the following:

• Placebo (dextrose) capsules with water
• Caffeine capsules with water
• Regular coffee
• Decaffeinated coffee
• Decaffeinated coffee plus caffeine

All of the "caffeine" trials (coffee or capsule) resulted in the ingestion of 4.45 milligrams of caffeine per kilogram of bodyweight (e.g. a subject weighing 70 kilograms would have been given 312 milligrams of caffeine). Each subject was tested at the same time of day, and there was at least one week between each trial.

Interestingly, the researchers found no differences in run time among the three trials in which coffee was ingested. The results were no different from the placebo trial.

In sharp contrast, six of the nine subjects had their longest run after taking the caffeine capsules, increasing their run time to exhaustion by approximately 10 minutes.

The average endurance time for the five trials is shown in the figure below. The increased endurance time after they were given caffeine capsules meant that subjects were able to run an extra 2-3 kilometers (1.2-1.9 miles) on the treadmill.

Why did caffeine but not coffee improve endurance performance?

Well, it wasn't because coffee somehow slowed the absorption of caffeine. When the subjects were given either of the caffeinated coffee solutions or the caffeine capsules, caffeine levels in the blood were very similar.

Instead, the researchers think that something in the coffee interferes with the performance enhancing effects of caffeine...

The caffeine was consumed in the same volume of coffee or water in the same period of time. It resulted in very similar plasma concentrations of plasma methylxanthines, but only when it was consumed independent of coffee was there an enhancement of endurance. Thus it appears that some component(s) in coffee interferes with the normal ergogenic response of caffeine.

When coffee beans are roasted, ground, and extracted in hot water, there are literally hundreds of other compounds dissolved along with caffeine. These include nicotinic acid, opiate-receptor antagonists, and cholinomimetics. And it appears that one or more of these compounds somehow "antagonizes" the effects of caffeine.

For example, a study in 1992 showed that when an "unidentified cholinomimetic compound" found in both decaffeinated and regular coffee was injected into rats, it led to an "abrupt depression" in both heart rate and blood pressure, whereas caffeine has the opposite effect [2].

In short, if you want to benefit from the performance-enhancing benefits of caffeine, you're better off using pure caffeine rather than drinking coffee.

About The Author
Christian Finn holds a master's degree in exercise science, is a certified personal trainer and has been featured on BBC TV and radio, as well as in Men's Health, Men's Fitness, Muscle & Fitness, Fit Pro, Zest and other popular fitness magazines.