This has a huge advantage for students, who generally need to carry heavy loads of books on their back. (goodereader.com)
Big arms are built by training with heavy loads for many reps, and it's true that lower rep ranges are ideal for building strength not size. (fitnessandpower.com)
This distributes the weight of the bag more evenly, allowing you to carry heavier loads with less stress on your back and shoulders. (geekwrapped.com)