A marathoner is someone who runs marathons, which are extremely long races of 26.2 miles. Running that far takes months of training: marathoners gradually build up their endurance, running longer and longer distances each week until their bodies can handle the full race.

Completing a marathon requires serious dedication. Most marathoners follow training schedules, pay attention to what they eat, and plan their lives around long weekend runs. During the race itself, they need mental toughness to keep going when their bodies want to stop, usually running for three to five hours without a break.

Some people become marathoners to challenge themselves, while others do it to raise money for causes they care about. The Boston Marathon, held every April, is one of the world's most famous races. Not everyone who runs is a marathoner: you earn that title through the commitment and achievement of training for and finishing those grueling 26.2 miles.