<P> A rubber ball was always used . Its size and weight varied over the centuries . Most historians assume a weight of 3--4 kg and a size of a skittle ball . The existence of a caoutchouc tree was necessary to produce the ball . These trees were found in the tropical regions in the Maya territories . </P> <P> The usual dress for MBG players is known from iconographic and figural findings . These show leather protection mainly at the hips and the chest, but sometimes also at the knees and the arms, though very seldom at the feet . The clothing was used to protect against the impact of the ball . The protected parts of the body were used to strike the ball . Some players would wear head dresses (like deer heads) for ritual reasons . </P> <P> Variations in the MBG occurred over the centuries as they have in modern ball games over years of use . Despite the variations, it would appear that the physical loads of MBG were most similar to those of soccer - tennis . Most likely the players of ballgame manifested a heart rate and blood pressure responses consistent with physical loads of light / moderate intensity, in the range of 4.5--5.5 METs . Thus, the cardiovascular demands of popular sports seem to have remained relatively similar through several millennia . </P>

Why was great skill required of the athletes who played the mayan ball game