Early but not too early running...

 No one knows when running became a recreation but races of 3200m (4 laps between two pillars 800m apart) took place in Egypt 3800 B.C.

Running was a part of the ancient Olympics; in fact for the first 13 Olympiads a sprint race was the only event, although longer races and other events were added to the programme over the years. The first Olympics were held in 776 B.C. and continued for almost 1200 years. At first the Olympics were religious festivals honouring various gods and the idea of physical perfection, but over time contestants lost their religious ideals and winning money became the prime motivation. The effects of music during training, diet, muscle structure and even physical differences were all fiercely argued over by trainers, athletes, scientists and even philosophers, like Plato. What did they wear? I can only find naked runners, or nearly naked runners in my research for Ancient Greek running so, I assume, not much...
(http://en.wikipedia.org/wiki/Running_in_Ancient_Greece)

Of course, running was important in many other cultures and there are records of Native Americans having races lasting several days, as discussed in previous blog posts. (see Tehmeru Posts)

In England the nobles of the 17th century took great pride in the running ability of their footmen, arranging races and betting heavily on "their man". In the 16th century cross country was an integral part of the public school system with "hare and hounds" and "paper chases" popular events. By the 19th century professional running was popular, and betting was part of the attraction. Professional runners (and walkers) of the time trained with steady runs plus time trials with long brisk walks a regular training activity. Many were training twice a day, so the practise of big mileage was common well before Lydiard.

 There is evidence that women participated too, but more for fun and it was rarely with men.