Sandbags are usually made from canvas or plastic and are filled with inners that contain sand or gravel. The load in a Sandbag isn’t fixed which makes them excellent for building grip strength.
The Bulgarian bag is more a specialized bag and used by many wrestling and MMA athletes. The Bulgarian bag is excellent for training in the transverse plane and building rotational core strength.
Water bags are the most advanced style of bag. The water inside the bag constantly moves from side to side throughout the movement which forces the entire body to engage to stabilize the load.
The bag we’ll be focusing on throughout this course is the Power Bag as it’s the most commonly used bag in commercial gyms.