For most westerners Japan is the country of sushi, samurai, aiki-do and sumo. The last one is a type of wrestling between fighters with enormous weights.

Sumo is a ritual fight, and the combatants make prayers to the gods before wrestling. The aim of sumo is that the fighter must throw his adversary out of the circle in whose center they wrestle using sheer physical force.

The origins of sumo can be placed during mythical times, when according to legends, gods fought between them, the winners being the strongest. Japanese chronicles tell us about wrestling demonstrations organized during the empress Kogyoku (642-645).

In our times, professional championships are organized. A championship can last 2 weeks and after numerous matches, the fighter who achieves the highest number of victories is acknowledged champion.

Fights take place on a square arena, with a diagonal of 4.5 m (15 ft) and a height of 50 cm (1.6 ft). To achieve victory, a fighter need to put his adversary out of the ring or throw him on the floor. The fighters have special hairdos and adornments and specific grunts and yells are aimed to disconcert the opponent. Any part of the body, except the soles or the feet, must not touch the floor,otherwise the fighter is considered defeated. Biting, hair pulling, stomach or chest blows are forbidden.

The selection of the fighters is made following strict criteria. If the young man is under 18, he must have a height over 1.7 m (5 ft 8 in) and a weight of 70 kg (155 pounds). If he is over 18, the minimal height is 1.73 m (5 ft 9 in) and weight of 75 kg (165 pounds), as in the ring weight is a main advantage.

Still, an excessive weight can be a problem for maintaining balance, as the fighter can fall easily "like a boulder". Training takes place each morning (between 5 to 11 a.m.) and the afternoon is spare. Due to the tough training, the sumo fighters have an enormous power in squeezing and back muscles.

To reach the weights of 120-150 kg (264-330 pounds), diet is very important. Breakfast is consumed usually after training; it is made of a hotchpotch, in two variants: one rich in fish and another rich in chicken meat with many ingredients, including season vegetables. The fighters sit around the tureen and eat from it. They must finish 5 to 6 servings of rice and then take 2 meals until the evening.

You may see sumo weird and unhealthy, but researches showed that normal-weight persons who are sedentary and unfit are at a much higher risk of mortality than the obese fighters who are active and fit. Despite their ripples of fat, super-sized Sumo wrestlers have a better metabolic profile than some of their slim, sedentary spectators.