Caffeine is one if the most consumed stimulants known to man. More than 82 percent of the population consumes caffeine. It is present in coffee, tea, soft drinks, chocolate and in many energy drinks. Like most stimulants , it increases your heart rate , and speeds up your central nervous system. There are a number of reasons why drinking coffee before a workout can increase weight loss. It will speed up your metabolism, providing a temporary metabolism boost. Caffeine has also been found to enhance an athletes performance during endurance activities. Coffee also has a diuretic effect that will contribute to weight loss after a workout. A cup or two of your morning joe may help jump start that fitness program!