饭后百步走，活到九十九

A folk health proverb of disputed origin (often loosely attributed to traditional Chinese medicine and to the Ming-Qing physician Cao Tingdong 曹庭栋). Modern medicine has partly vindicated it: light walking after meals modestly improves blood sugar regulation. The number 九十九 rhymes with 走, which is why this version stuck rather than other round numbers.

Often paired or contrasted with 饭后一支烟，赛过活神仙 ('a smoke after a meal makes you feel like a living immortal') - an older saying now used ironically as anti-smoking sentiment grew.