k pop idols have such flat stomach because they go on diet, because of their tight scheduleof promotions,shows and dance practice. they have regular exercise which helps them lose or maintain weight.
if you are looking to get a flat stomach by yourself , try going on a diet but dont go extreme from the first day. make sure to take it slowly day by day, by doing these, it wll become easier .
Do exercises like sit-ups,cruching,twisting and running may help
Now that you have come to the end of the article,K pop idols only have flat stomach because of their diets and dance practice .