You are not a camel and you dont want to wear a backpack while you train for the marathon. The CamelBak Montara Hydration Lumbar Pack solves your need-water crisis and your nothing-on-the-back-please preference. Fill the 1.3-liter water reservoir, stick your keys in the two zippered pockets, and stash energy gel in the two stretch mesh waist-belt pockets for easy access. Then clip the Montara on and cinch the side compression straps down. CamelBaks strap management system secures the ends of the straps so they wont flip up and down with each stride.