Unless you complement your carbohydrate source with protein, your body will start to digest its own protein (muscle tissue) for energy after about 90 minutes of hard exercise. So when your training takes you beyond the range of HAMMER GEL alone, you can rely on SUSTAINED ENERGY with its 7:1 carbohydrate : protein ratio. SUSTAINED ENERGY contains a superior blend of complex carbohydrates, a precise amount of protein, and a few carefully selected micronutrients that all work synergistically to provide consistent, long-lasting energy. With SUSTAINED ENERGY, you'll have 100% confidence in your fuel, even during your longest and hardest training sessions and races. Without any added flavoring or sweeteners, it has a pleasant neutral flavor.
PERPETUEM, on the other hand, has a pleasant orange/vanilla 'dreamsicle' flavor and is also a superior nutrition source for carbohydrates, protein and fat. It is formulated specifically for athletes attempting endurance events lasting more than 2 hours. For ultra endurance events, especially those that extend beyond the 12 hour mark, and may even go into the multi-day realm, PERPETUEM has no equal.