Caffeine is a part of most people's daily diets. It is found in many foods and drinks. Research has shown that one cup of coffee has positive effects on decision-making, alertness and reaction time. But, how does caffeine affect your exercise performance? First, more caffeine is not necessarily better. One or two cups of coffee will help your exercise performance. Researchers from the University of Luton reviewed 39 published caffeine studies. They found that caffeine users improved endurance exercise performance and short/high intensity exercise performance by 12.4% when compared to groups using placebos. The risks associated with moderate caffeine use are pretty small. If caffeine is part of your diet, use it wisely to help your exercise performance.