Full-body Weighted Bag for Bulgarian Bag Training also known as the Bulgarian Training BagĀ is a crescent-shaped exercise equipment used in strength training, plyometric weight training, cardiovascular training, and general physical fitness. The bags are made of leather or canvas and filled with sand; they weigh from 11 pounds (5.0 kg) to 50 pounds (23 kg) and have flexible handles to allow for both upper and lower body training, and for building grip strength