Ключевые слова: 3, 2017, adult, asphalt, athlete, athletic, athletics, caucasian, competition, competitive, endurance, exercise, foot, forest, group, half, jogging, leader, leading, leg, male, man, marathon, nature, outdoor, park, people, race, real, rivalry, road, run, runner, running, shoes, sport, sportswear, spring, three, track, trail, woods, young,