A marathon runner is an athlete who competes in long-distance races, covering 26.2 miles. Synonyms for marathon runner include distance runner, long-distance runner, endurance runner, and ultra-runner. These terms are interchangeable to describe athletes who specialize in running races that range from 10 kilometers to 100 miles. Distance runners are focused on developing stamina, speed, and resilience to endure long races. Endurance runners are known for their ability to perform consistently over extended periods while ultra-runners take things to the extreme with races lasting up to 24 hours. All these synonyms for marathon runner signify a significant physical and mental commitment to the sport, showcasing the ultimate human spirit of resilience and perseverance. So, these athletes are truly remarkable!