Regular, moderate aerobic activity, like walking, is a great way to perk up and ease your fatigue. Caffeine might give you quick energy, but isn't a great solution. It can keep you awake at night, which can make you sleepier during the day. A 20-minute power nap can also revive your energy. However, when you nap during the day, you may not be tired enough at bedtime to get a full, good night's sleep. Take a quick walk to re-energize!