Evenly distributed weight in the front and back. Each weight is a solid 2.5 lb. rounded metal bar. Easily remove weights by lifting the flaps and sliding them out of their pocket. The 100 lb. short vest is a 50 lb. vest with a 50 lb. removable attachment (basically, another vest without padded shoulders which slips over the 50 lb weight vest and velcros to it and then is held in place with a belt system).