If the kidneys hurt after jumping rope, check the color and smell of the urine. If the urine smells and is cloudy or yellowish, that means that the kidneys are weak, there is too much blood acidity in the kidneys, and there may be uric acid crystalization.
Drink hot diuretic teas, a lot of hot diuretic teas, not cold water, not soft drinks, but hot hot hot diuretic teas. Reduce the toxicity of the acidity in the kidneys, wash out the uric acid and anything that may be causing the kidney pain, like little rocks of calcium in the kidneys that doctors like to call kidney stones.
Increase the hot tea intake on a regular basis. Do not drink anything cold. When the urine is clear and does not smell, then go jump rope and see if the kidneys still hurt.