Final answer:
Emanuel Yarbrough, a massive athlete at 6'8" and 740 lbs, was known for his participation in sumo wrestling, a sport where such physical attributes can be advantageous.
Step-by-step explanation:
The heaviest man in the amateur division of his sport, Emanuel Yarbrough, was an athlete in the sport of sumo wrestling. Sumo is a competitive full-contact wrestling sport that originated in Japan and is characterized by participants who can be quite large in both height and weight. Yarbrough himself was not only tall at 6 feet 8 inches but also weighed in at an impressive 740 pounds, making him a formidable sumo wrestler during his time.