Fig. 1. Twenty-four-hour blood pressure profile after energy drink and placebo beverage consumption (n = 17).

Systolic blood pressure (a), diastolic blood pressure (b), mean arterial pressure (c). Beverages were consumed at similar morning hours (Time 0). An automated oscillometric blood pressure device performed measurements every 15 min during daytime and every 30 min during nighttime. Study participants were asked to note sleep and wake time on a separate protocol.