In Reply Dr Grasser and colleagues discuss the importance of longer postdrink blood pressure and heart rate observation periods and suggest that water would have been a more appropriate placebo drink.
First, with regard to duration of observation, our protocol was designed to follow closely the metabolism and bioavailability of caffeine. Oral absorption of caffeine from the intestinal tract is rapid and caffeine becomes completely bioavailable, reaching a peak plasma concentration 30 minutes after ingestion, whereas plasma half-life ranges from 3 to 10 hours.1
Svatikova A, Covassin N, Somers KR. Hemodynamic Responses to Energy Drink Consumption—Reply. JAMA. 2016;315(18):2018-2019. doi:10.1001/jama.2016.1115