So let's suppose I'm moving my arm back and forth. And as I move my arm back and forth, the muscle tissue begins to contract and ATP molecules are being produced by those muscle cells. So this is let's suppose that muscle cell and this is the nearby capillary that carries the red blood cells. Now, as these cells are exercising, they require a greater number of oxygen molecules to produce the ATP. And so inside the red blood cells, the Bore effect takes place. That causes hemoglobin to actually unload and release the oxygen which then travels into those exercising cells inside the cells in a process called aerobic cellular respiration.