The term 'Heavyweight Wrestling' can refer to a variety of different wrestling styles, but one of the most popular is SUMO, which is a Japanese style of wrestling. SUMO is a form of competitive full-contact wrestling where two wrestlers attempt to force each other out of a circular ring or into submission. The wrestlers, known as rikishi, wear traditional mawashi belts and use only their strength to battle. SUMO is considered to be one of the oldest forms of martial arts and is still practiced today.