FEEL sleepy after a long day at school? Need something to perk (使振奋) you up after a sweaty (大汗淋漓的) workout? Some of us may turn to energy drinks for a boost. But think twice next time – energy drinks can raise blood pressure to levels that could be unhealthy, according to a study presented in March at an American College of Cardiology meeting in San Diego. The effect was far greater in young adults who did not drink more than a small cup of coffee or another caffeinated (含咖啡因的) drink daily, according to the report.