Sports bags, also known as duffels are bags that are convenient to carry and big enough to carry all your sports equipment. Most sports bags are also waterproof as they are much outside in all weathers. Your sports equipment should therefore remain dry. There are compact sport bags of 35 liters, but also large sports axes of 140 liters or larger. It just depends on what you want to bring to the sport. A towel and clean clothes or even an entire sports equipment. Some large sports bags even have convenient wheels.