You bet: We need endurance fuel, and complex carbohydrates are the key ingredient. "You'll be burning a lot of carbs. Try for a mix of about 50 to 60 percent carbs, 20 to 30 percent protein, and 20 to 30 percent fat," says Neal Henderson, coordinator of sport science at the Boulder Center for Sports Medicine (BCSM). "Protein, especially on extended trips, is very important for muscle tissue regeneration." No need to haul a side of beef with you--half a gram of protein per pound of body weight daily will maintain muscle mass.
And it matters when you eat. Gobbling down a snack with some carbs within 30 minutes of stopping can help you recover better for the next day, says Henderson.