Action of Caffeinated and Decaffeinated Espresso on Autonomic Function

More than 80% of the population in the USA consume coffee each day. However there not many studies on change of heart rate variability and placebo effects after consumption of coffee. In our study we aim to test the following hypotheses: 1. Habitual caffeinated espresso coffee drinkers show an increase in blood pressure, heart rate variability and parasympathetic activity (high frequency band) of the heart. 2. Non-habitual caffeinated espresso coffee drinkers show an increase of blood pressure. The heart rate variability and the parasympathetic activity of the heart will decrease. 3. Caffeinated or decaffeinated espresso induces comparable changes in habitual or non-habitual coffee drinkers.