Drinking 32 ounces of an energy drink in a short timespan may increase blood pressure and the risk of electrical disturbances in the heart, which affect heart rhythm, according to a small study published in Journal of the American Heart Association, the Open Access Journal of the American Heart Association/American Stroke Association.

The study enrolled 34 healthy volunteers between the ages of 18 and 40 years. Participants were randomly assigned to drink 32 ounces of one of two commercially available caffeinated energy drinks or a placebo drink on three separate days. The drinks were consumed within a 60-minute period but no faster than one 16-ounce bottle in 30 minutes.

Researchers measured the electrical activity of the volunteers’ hearts by electrocardiogram, which records the way a heart is beating. They also recorded participant’s blood pressure. All measurements were taken at the study’s start and every 30 minutes for 4 hours after drink consumption.

Read more at American Heart Association