When we exercise, the muscles require more energy. They normally get this through the process of __________ respiration and so need more __________ and __________.
In order to deliver these substances the pulse rate __________ and we breathe __________. The diffusion of oxygen and carbon dioxide at the __________ surface and muscle cells is increased as there is a greater concentration gradient.
If the heart and lungs can't keep up with demand, then our cells will peform __________ respiration, causing a build up of __________.
__________ thermometers, and breathing rate and heart rate monitors, can provide more reliable data than traditional methods because their measurements are more __________ and can be made __________ excercising.