to walk one's legs off; have very sore legs; my dogs are barking
Have you ever walked so much your legs feel like boards? Next time that happens, say, "ashi ga bou ni natta."
Literally, "legs become staffs." This comes from tired legs getting as stiff as a board.
ichinichi juu aruita node, ashi ga bou ni natta.
I walked all day, and now my legs are as stiff as a board.
一日 ichi nichi -- one day
一日中 ichinichi juu -- throughout the day [adding 中 chuu or juu adds the meaning of "throughout" or "in the course of...": 一年中 ichinenjuu throughout the year (every day of the year); a common sign on stores that are open throughout the year is: 年中無休 nenjuumukyuu open throughout the year [literally, throughout the year, no resting]; this can be used for space too: 日本中 nihonjuu throughout Japan; 町中 machijuu throughout the town; 学校中 gakkoujuu throughout the school]