Sports and hydration backpacks are smaller with a profile closer to the body, wider straps and can come with water bladders and hip belts for running, cycling or hiking. Running hydration packs are the smallest and lightest, many under 2 litres and most under six litres. Compression straps across the top of one's body are common as are hip belts. Cycling hydration packs are six to ten litres sitting high on the back. Although daypacks are small averaging ten to thirty litres, all Trekking and Hiking hydration packs are generally the largest and heaviest. Thirty five up to sixty five litres and above are common.
I actually use this tote as a diaper bag, I have two children in diapers and it really works great for that. Aside from the way I use it, I think it's an over all great bag. A few issues: the elastic pockets on the sides seem to have lost their tension already, I don't put anything large or heavy in them to cause this, also the pocket in the back.. Wish it was larger, I don't really see the point of the zipper in the bottom of the pocket. The only other issue I have is the straps, wish they had some sort of padding on them, they tend to be a little hard on your hands if you're carrying anything heavy. https://i.pinimg.com/170x/7d/9a/c7/7d9ac7631c50158836bbde68b75719fa--thirty-one-products-thirty-one-gifts.jpg