A triathlon is defined as the completion of three continuous and sequential endurance disciplines. While many variations of the sport exist, a triathlon, in its most popular form, involves swimming, cycling, and running in immediate succession over various distances.
Ask anyone who likes to participate in a triathlon why they like them and they’ll tell you triathlons are great way to stay in shape. As a bonus, you can compare your completion times against other participants and against yourself to attain your personal best time.