What we do know is that caffeine enhances cognitive functioning . Many studies report increased arousal and vigilance in occupational situations and some studies report improved visual information processing and reaction time during computer based and pen-and-paper tests in subjects. Athletic performance has been reported to be enhanced by caffeine prior to competition as well. But what about sex you ask?...well there was a recent study from Southwestern University that found caffeine increased the female libido in experiments on rats. Apparently the effect was caused by it stimulating the part of the brain regulating arousal. But the researchers say a similar effect was only likely to be repeated in humans who do not drink coffee regularly. Sorry coffee drinkers, your Starbucks Grande Dark Roast might not act as an aphrodisiac after all. But it can help you to stay alert and awake and focused at night so you and your partner can indeed enjoy some terrific "whoopi".
Now be careful all you lovers, too much caffeine can have some not too good side effects such as dehydration, anxiety, headache and sleep disturbances. It can raise your blood pressure, and prevent your kidneys from reabsorbing calcium. Ruxton (2008) concluded that the range of caffeine intake that appeared to maximize benefits and yet minimize risks was 38-400 mg per day (one cup of coffee has about 80-180 mg of caffeine in it).
So, like most things in life, enjoy your coffee in moderation, and who knows, if your not dehydrated, anxious, have a headache, or sleep deprived...you might just end up hanging a sign on your front door every night that says: "IF THE HOUSE IS A ROCKIN', DON"T BOTHER KNOCKING".