Hardly any other stimulant is associated with as many prejudices as coffee. One of them is that coffee before training wakes you up and prepares you for the effort ahead.
Study 1:
However, Swiss researchers have now discovered that just two cups of caffeinated coffee reduce the blood flow to the heart and thus significantly reduce the actually positive effect of endurance training. In their study, they were able to prove that blood flow to the heart decreased by 22 per cent after drinking caffeine during physical exercise. The difference was even more significant when training at high altitudes, where the oxygen content of the air is lower anyway. Endurance athletes who consumed caffeine before this training had 39 per cent lower cardiac blood flow than those who had not consumed coffee beforehand. According to the scientists, the caffeine blocks receptors that otherwise send the vascular walls in the heart the command to expand during endurance training. The researchers therefore recommend avoiding excessive coffee consumption before exercise - especially in the mountains.
Study 2:
At the same time, studies have shown that the abundant caffeine contained in coffee also has a stimulating effect on athletes under stress. Scientists from the Universities of Kent and Sao Paulo have investigated exactly how the active ingredient delays signs of fatigue during high-intensity road bike training. For the study, endurance athletes had to complete an ergometer test until they were completely exhausted, once with the addition of caffeine and once with caffeine-free placebos. With caffeine, the test subjects were able to cycle twelve per cent longer on average, as they felt less exhausted - even though their muscles were just as exhausted. Caffeine does not help against tired legs, but it stimulates the nervous system and can thus trick the subjective feeling of exertion.
Conclusion:
What initially sounds contradictory can be easily combined in practice: Study one assumes a high caffeine intake immediately before training. The amount of caffeine taken in tablet form was equivalent to at least two cups of coffee. Those who do not drink large amounts of coffee immediately before a heavy workout do not have to fear any cardiovascular consequences. During prolonged exercise, (moderate) caffeine intake before or during sporting activity increases the willingness to perform - a neuronal consequence of coffee consumption. In other words, every road cyclist can continue to drink a cappuccino or espresso before a ride or during a break with a clear conscience.
