Ironman just switched to age-grading, which is just as simple and already used by many runner training plans and race calculators. https://www.ironman.com/news

Ironman just switched to age-grading, which is just as simple and already used by many runner training plans and race calculators. https://www.ironman.com/news/age-group-qualification-system https://www.ironman.com/news/age-group-qualification-system