To wake up when you're feeling tired in the middle of the day, try taking a break from your current task and going for a short walk to get your blood pumping. Or, you can throw on some upbeat music for a few minutes to wake yourself up. Alternatively, try snacking on some citrus fruit if you're feeling hungry, which can boost serotonin and put you in a better mood. Just try to avoid drinking coffee since the caffeine might make you crash, and instead drink some ginseng tea for a ...