A Answers (3)
National Academy of Sports Medicine answeredCaffeine has so many effects on so many different body systems and processes that one small study is not enough to take away anything conclusive about the way caffeine will affect you. My advice is to wait for more conclusive research on caffeine and physical performance, but until then do not get overly worked up about it. If you are a healthy individual and you want that daily cup of coffee, it should not hurt you. But if you are looking for that edge, look for it in your daily training, not in your morning coffee mug.
Kenneth Johnson , NASM Elite Trainer, Fitness, answeredThe exact mechanism(s) by which caffeine helps performance is not clear, though traditionally it was considered that caffeine increased fat oxidation. Caffeine consumption stimulates lipolysis, as does exercise, both of which provide more "fuel" for the muscles to burn.
Another mechanism may be that caffeine blocks the perception of fatigue and results in a lower rate of perceived exertion to the athlete. Here caffeine works by stimulating the Central Nervous System, acting antagonistically on adenosine receptors and thereby sustaining forceful muscle contractions. This mechanism would explain how caffeine helps anaerobic exercise.
In discussing the research it is important to remember that “coffee” does not mean the same thing as caffeine. Coffee contains many other biologically active compounds besides caffeine, some of which block the action of caffeine. The majority of studies on the ergogenic properties of caffeine provide that caffeine in capsule, not as a cup of coffee.
A 2008 research project utilized an endurance treadmill test where participants were given a placebo, decaffeinated coffee, caffeinated coffee, or alkaloid caffeine via capsule. Those who ingested the alkaloid caffeine -- but not caffeinated coffee -- had a 31% increase in endurance.
Gary Wenk, Psychology, answeredThe evidence is limited, however most studies do reveal some small benefits. The combination of coffee and exercise produced a higher lipolytic (fat-burning) response than just exercise alone. Caffeine can induce the release of endogenous opiates and may lessen the pain assocaited with exertion. For example, in studies of athletes, caffeine did not modify the delay before feeling exhaustion with exercise but it did attenuate the perception of the effort required while exercising. Also, caffeine's effects were more pronounced at high altitudes (above 2900 meters), e.g. when skiing. Once again, caffeine increased the delay to exhaustion. The effects at high altitudes is also thought to be due to caffeine's ability to increase the mobilization of fatty acids from body fat.