Created for daily training and competition, GU Energy Chews pack energy-dense calories in a portable packet to help sustain energy demands of long duration activities. The 90-calorie packet contains carbohydrates to keep you fueled while delaying bonking by sparing your glycogen stores. Sodium, the primary electrolyte lost in sweat, aids in hydration by maintaining water balance. The branched-chain amino acids (leucine, valine, isoleucine) may reduce mental fatigue and decrease muscle damage.