Magnesium is a mineral that contributes to a normal protein synthesis, a normal functioning of the muscles and a proper electrolyte balance. In addition, magnesium contributes to the reduction of fatigue.
Caffeine is a stimulant. Caffeine is quickly absorbed in the blood; half of it is already absorbed within 3 to 4 minutes after eating or drinking. You will experience the effects within 0.5 hour to 2 hours after having a coffee or caffeine drink. An amount of caffeine comparable to 1 or 2 cups of coffee (160 mg) has a stimulating effect on adults’ concentration and performance. It gives a feeling of increased energy and dispels feelings of fatigue. Caffeine also slightly improves memory, alertness and motivation. Larger quantities do not result in a bigger effect. For athletes, caffeine can support longer periods of exercise.
Drinks with caffeine simply provide fluids to the body. It is often thought that drinks with caffeine are diuretic. That is not true. The body does not losemorefluid by drinking coffee, for example. Caffeine only ensures that the fluid leaves the body faster, because it stimulates the kidneys.