Video narration
How does breathing hard during exercise help your blood deliver oxygen and remove carbon dioxide at the same time? Working muscle receives oxygen-carrying hemoglobin. It adds carbon dioxide, making blood acidic. That lowers hemoglobin's oxygen affinity, so it releases oxygen where needed: the Bohr effect. In lungs, oxygen binds hemoglobin and helps it release carbon dioxide for exhalation-the Haldane effect. So Bohr unloads oxygen in muscle; Haldane helps oxygenated blood unload carbon dioxide in lungs.