Effects of caffeine on athletic performance

For many people, starting the day without a hot cup of coffee is unimaginable. This is because the caffeine contained in coffee wakes you up, boosts your circulation and increases your ability to concentrate. On average, every German drinks almost half a liter of coffee every day! Caffeine is also said to improve performance in sport. Is that really true?

Table of contents

1. The active ingredient caffeine
2. Liquid deprivation - myth or truth?
3. The absorption and effects of caffeine
4. Caffeine and sport

The active ingredient caffeine

Caffeine (also known as caffeine) from coffee beans was first isolated in 1819 by the chemist Friedrich Ferdinand Runge after he was encouraged by Johann Wolfgang von Goethe to study the beans. The full chemical name is 1,3,7-trimethyl-2,6-purinedione or 1,3,7-trimethylxanthine for short. In its chemically pure form, it is a white, odorless, crystalline powder with a bitter taste.

The active ingredient is not only found in coffee beans, but also in numerous other plants. To date, there are around 100 different plant species in which it can be found. These include, for example, the berries, seeds and leaves of the tea bush and mate plant as well as the cocoa and cola tree. The natural ingredient serves the plants as protection against predators and parasites.

Caffeine is a pleasure and stimulant that has a stimulating effect on our brain and nervous system. It therefore stimulates heart activity, increases blood pressure, dilates the bronchi and blood vessels and stimulates muscle activity and diuresis (urine excretion via the kidneys). It also influences mood and the ability to concentrate. If the intake is too high (over 200 mg), nervousness, insomnia, headaches, an increased or disturbed heart rate and digestive disorders can occur.

Our protein powders in the cappuccino flavor also contain caffeine.dehydration - myth or truth?

Caffeine stimulates kidney function so that the fluid ingested is excreted earlier, but this has little effect on the amount of fluid excreted. Studies show that coffee drinkers excrete around 84% of the fluid they consume after 24 hours, whereas water drinkers excrete 81%, which does not make a big difference. Moderate coffee consumption is therefore included in the daily fluid intake.

The absorption and effect of caffeine

The active ingredient is almost completely (90%) absorbed from the gastrointestinal tract within 20 minutes of oral intake and enters the bloodstream. It is absorbed most quickly when it is dissolved in a liquid, for example in the form of a coffee or protein shake. Due to its lipophilic properties, caffeine can cross both the blood-brain and placental barriers.

Caffeine is a so-called purine alkaloid. Purines have important functions in the energy metabolism of our body cells. Of particular importance in this context is adenosine triphosphate (ATP). ATP is an energy carrier that provides the body with energy for important processes. The breakdown of ATP produces adenosine. If adenosine docks onto the adenosine receptor, the body or nerve cells are signaled to work less.

As both substances, caffeine and adenosine, have a chemical similarity, caffeine can also bind to the adenosine receptors and thus block this receptor for adenosine. As it prevents the calming effect of adenosine, the nerve cells continue to work at full speed and there are no signs of fatigue.

The effect lasts for around 4 hours.

Caffeine and sport

Caffeine increases athletic performance. However, the exact mechanism responsible for this increase in performance is still unclear. However, it is known that it delays symptoms of fatigue and reduces the perception of pain. It also promotes muscle contractility and has a vasodilating effect, which improves the supply of oxygen and nutrients to the muscles.

Because of these positive properties, the active ingredient used to be on the World Anti-Doping Agency (WADA) list of banned substances. However, it was removed from the doping list again in 2004. However, this was not because it is not effective, but because the defined limit value of 12 μg per liter in urine is not meaningful. Due to individual differences and habituation effects, it is not entirely clear which quantities are really effective.

Caffeine and endurance sports

Many studies prove the positive effect of caffeine on endurance sports. As little as 3 mg of caffeine per kilogram of body weight  (i.e. around 200 to 300 mg or two to three cups of coffee) leads to improved endurance performance.

For example, researchers found that cyclists and runners were able to achieve a higher endurance performance when taking the active ingredient.

Caffeine and weight training

In recent years, numerous studies have also been carried out in the field of weight training to determine the effect of caffeine on weight training.

In a study conducted in 2011, 13 untrained men were asked to bench press weights. The test subjects who had taken caffeine (5 mg per kg body weight) before the exercise were not only able to perform more repetitions, but also lift heavier weights. These test subjects also felt stronger and tired less quickly than the placebo group. British researchers also showed that an improvement in the contractile strength of various muscle groups occurs in trained strength athletes if they had previously ingested the active ingredient.

Sources

• https://de.statista.com/themen/171/kaffee/
• http://www.kaffee-wirkungen.de/wirkungen/psyche-und-koerper/sport-und-physische-leistungsfaehigkeit/
• https://www.ncbi.nlm.nih.gov/pubmed/21157384
• https://www.ncbi.nlm.nih.gov/pubmed/25144133
• https://link.springer.com/article/10.2165/00007256-200131110-00002#page-1
• http://edoc.sub.uni-hamburg.de/haw/volltexte/2014/2345/pdf/BA_Mizevaite_Jurgita.pdf
• Wolfgang Beiglböck (2016) Caffeine - stimulant or addictive substance? Springer-Verlag Berlin Heidelberg, 1st edition

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