Whether sit-ups are good for the kidneys is divided into normal people or people with kidney disease. For normal people, it is definitely good for the kidneys. Sit-ups are strenuous exercises for the waist, which can accelerate the circulation of body fluids, promote the discharge of toxins, and enhance the function of the waist muscles. But for patients with kidney disease, such as pyelonephritis, glomerulonephritis or renal cysts, renal failure, strenuous visceral exercise can cause friction in the kidneys. If the rupture of large cysts occurs, kidney stones occur peristaltic acceleration, the possibility of increased pain, so it is not recommended to perform such strenuous exercise as sit-ups. You can appropriately run or race walking and other sports. People with poor kidney function must pay attention to rest, avoid strenuous sports, quit smoking and limit alcohol, avoid eating spicy and stimulating food, while drinking more water, urinating regularly, eating more vegetables and fruits, alkalizing the urine, etc.