Staying hydrated and on top of carbohydrate intake are the two primary nutrition goals for endurance exercise. One of my absolute favorite foods for hiking or mountain biking are boiled and salted potatoes. When I tire of sweet bars and trail mix, potatoes provide the potassium, sodium, and carbohydrates I need. Just boil fingerling potatoes until fork tender and toss with enough olive oil to make coarse kosher salt stick.
Just three potatoes (about 100 g) contain about 20 g carbohydrate and 400 mg Potassium and they’re a great budget choice for athletes. Enjoy!