《汉书·传·王贡两龚鲍传》
与之相反，宫中马厩中的马匹却因终日饱食粟米，致使人们为其过于肥壮而发愁，并且担心它精力旺盛而容易发怒，便天天让它遛达活动，用以消耗它过剩的精力。
人至相食，而厩马食粟，苦其大肥，气甚怒至，乃日步作之。
Conversely, the horses in the royal stable are so full of millet from eating all day that people worry because they are too fat, and for fear that they are full of energy and easy to get angry, they take them out for a walk every day to expend their excess energy.