Padded shoulder and waist straps make running more comfortable, especially when you have to carry a few pounds on your back. Thin straps don’t distribute the weight of your backpack, causing more tension to certain areas, and increasing the possibility of chafing. The larger the straps on your bag is, the more comfortable it will be. Larger straps do add weight to the bag, however, the even distribution of this weight can actually make them feel lighter and more comfortable.