Running event participation is declining. According to an international study by RunRepeat, participation peaked in 2016, with a total of 9.1 million race results. By 2018, it had fallen to 7.9 million results, for a drop of 13 percent. In the long term, however, between 1986 and 2018, race participation registered an increase of 57.8 percent. Researchers also found that 5K and half-marathons are still the most popular distances to run, with 2.9 million and 2.1 million runners completing the courses in 2018, respectively. However, half marathons declined by 25 percent in the last two years while 5Ks declined by 13 percent. The study analyzed 107.9 million race results, including participants from around 209 countries at more than 70,000 events between 1986 and 2018.