Gnarly Sports Nutrition nailed it with the Fuel2O, a double-serving, vegan-friendly drink mix. The powder comes in three flavors; I tried Tropical, which gave me energy for hours. Filled with all sorts of electrolytes, including magnesium, potassium, calcium, and sodium, the Fuel2O provided an energy boost without the shakiness I get from coffee. Plus, the pick-me-up is sustained. I chugged it before a big hike and was noticeably less tired than normal. $29 for a box of 10.