About 5 years ago on the High Sierra Trail, a group of ladies in their sixties doing the entire 9 day HST hike were zipping along with hefty packs. They said one of their secrets was using the Cytosport (company name) Cytomax Recovery Drink. This drink is still being sold today but no longer being manufactured, I contacted the manufacturer and got suggestions for a replacement. I have studied their ingredients and the spreadsheet at this link shows my findings.
Every two hours on the trail, I make a replenishment drink to re-energize me, it consists of a 1/2 doze of the Cytomax drink recovery powder, a package of Emergen-C Heart Health Black Cherry Powder, and 1 energy drink (alka-seltzer type/fizz) tablet from SuperFlyEnergy.