A triathlon includes three circuits: swimming, cycling, and running. Each segment tests different athletic skills and endurance levels, beginning with the swim, followed by a bike ride, and finishing with a run. The combination of these three disciplines challenges participants both physically and mentally. Athletes must train extensively to excel in each area and transition smoothly between events. Triathlons vary in distance, with formats like Olympic and Ironman, attracting a wide range of competitors from beginners to elite athletes.