Probably. But is it safe for you? Probably if your cardiovascular system is healthy. However,chances are, if your are obese, your heart and your arterio-venous system are highly overworked. Your veins and arteries are most likely accumulating fats and calcium deposits that could make you a candidate for heart failure while engaged in your sports.
Unlike exercise which will make you trim, sumo will encourage you to gain more wieght as it is what you need to win your game.
