The Bulgarian Bag (Bulgarian: Българска торба / Български чувал), also known as the Bulgarian Training Bag (Bulgarian: Българска тренировъчна торба), 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.
The bag can be used as a free weight in various simple and dynamic movements like pushing, spinning, swinging and rotating, and added to one’s body weight to perform jumps, squats, push-ups, pull-ups and power crunches. Many sample workout routines have been posted on the Internet.
The Bulgarian Bag strengthens and increases the muscular endurance of the grip, wrists, arms, shoulders, back, legs, and rotational muscles. It also aids in building core musculature, coordination, and improving overall shoulder and joint mobility. Because of its shape, material and construction, Bulgarian Bag can be used to develop quickness and agility in ways which solid iron weights and circuit machines cannot.
Variable angular resistance
The Bulgarian Bag breaks the tradition with static resistance devices such as free weights which adhere to a singular plane of motion (i.e. creating resistance by pushing or pulling weight away from and toward the body), by using accelerating and deceleration movements to swing and spin the bag at various angles to athlete’s body. This results in the Bulgarian Bag’s ability to increase overall body strength and agility.
The multi-angular approach to gravity, momentum and inertia in physical exercise has been termed Variable Angular Resistance training in some use.
After cardiovascular exercise or weight training, the body continues to need oxygen at a higher rate than before the exercise began. High intensity bouts of exercise with the Bulgarian Bag increase metabolic rates higher than traditional weight training and cardiovascular activity because the exercise includes both weight training and fast dynamic movement.
Originally referred to as oxygen debt, this post exercise aerobic effect was first hypothesized by A.V. Hill and H. Lupton in 1922. They theorized that the body needs to replace the oxygen used by working muscles during mild to intense bouts of exercise. More recently, researchers have used the term ‘excess post-exercise oxygen consumption’ to describe the different events that occur as the body restores itself to homeostasis, or rest. The body’s metabolic rate will be raised for a longer period post- exercise from high intensity bouts of exercise. Depending on the level of stress and intensity of exercise, metabolic increase can be seen for up to 18–24 hours.
Exercises with Bulgarian Bags, like any other plyometric shock-training exercises, involve an increased risk of injury due to the large forces that are generated during acceleration, and should only be performed by well-conditioned individuals or under supervision. For more information on risks involved in plyometric training, see safety considerations in plyometrics.
Because the handles of the Bulgarian Bag are flexible and not rigidly fixed to the body of the equipment, it is harder for an athlete to transfer the weight of the equipment to his or her forearm and arm muscles than with traditional iron weights, and more load is carried by athlete’s wrists. The use of wrist wraps may therefore be advisable for people with weaker wrists to provide additional support.