If you had to guess whether energy drinks were good or bad for your heart, you'd probably go with "bad." Mainly because your heart sometimes feels like it's going to explode after you drink one!

Well, according to a new study out of the University of Siena in Italy, that's not true. Believe it or not, a doctor there found that drinks like Red Bull, Monster, and Rockstar actually improve your heart's performance.

In this study, he had healthy people in their 20s drink an energy drink, then measured their blood pressure, heart rate, and heart function. He found they cause a slight increase in blood pressure and heart rate, but also cause an increase in myocardial function which helps your heart beat regularly and efficiently.

Of course, this is just about the only study EVER to find the positive health benefits of energy drinks, so take it for what it's worth.