Swim Your Age
noun - Swim Your Age is an open water swimming feat that requires a swimmer to swim non-stop, without a wetsuit, equal to the same or greater number of kilometers as their age. It is a difficult metric in the world of marathon swimming that becomes increasingly difficult the older the swimmer is.
A 25-year-old can swim their age if they swim a 25 km swim. But a 50-year-old must swim 50 km to also achieve this same goal.