The 100 meter dash is a quick and short run requiring explosive speed. on completion of the dash the runners will continue to breathe hard for several seconds to minutes even though they are no longer running. which of the following is the best explanation for why this is so?

Because you are running so fast, your body produces a lot of lactate. Along with this lactate comes a hydrogen ion (H+), and you can’t have too many of these in the body because they will make the body fluids acidic. So the body "buffers" the H + using biocarbonate (HCO3-) which produces CO2 and H2O. This raises the CO2 concentration of your blood, which is detected by receptors in the aorta and carotid arteries, and the respiratory centre of the brain, which then causes you to breath more deeply and more frequently.