Does your energy tank at 3PM? Take a break! Our circadian rhythm causes our body temperature and hormone levels to drop about then, leaving us sleepy and sluggish. But Louisiana State researchers found people who work at computers all day, but took 15-minute breaks every 2 hours – solved problems faster and more accurately. Because switching tasks requires the brain to re-focus, which can boost your energy. Even if your new task is a walk down the hall to chat with a coworker.