How were sports made?

Sports have been around since the dawn of man. Ancient Celts did wrestling matches, the axe tosses, archery contests ( these are still done today), the caber toss, and throwing rocks as sports. Horses races and gambling games have been around for thousands of years. The Mayans and ancient Incas had a basketball type sport. Not to mention the first massive arena was made in Rome. and the games/sports played there. The Colosseum could hold 50,000 people, used elevators to get animals/men to the floor of the arena, and they also held sea battles.