The modern Summer Olympic Games have been held every four years since the first Games in 1896 and Olympic records are recognised by the International Olympic Committee (IOC) in each event. The athletics events, which take place at each Games, are divided into four groups: track events, field events, road events and combined events. Women compete in 23 athletics events during the Games, and men compete in 24; while 21 of the events are the same for both men and women, men exclusively compete in the 50 km walk, the women's combined event is the heptathlon while the men compete in the decathlon, and the short distance hurdles for women is contested over 100 m, ten metres shorter than the men's event.