during exercise your muscles contract meaning that they will be using up glucose, therefore blood glucose level needs to be maintained . Negative feedback will then increase the blood glucose level by secreting glucagon (alpha cells in pancreas) this will then make the liver to convert glycogen into glucose, which will then be released and absorbed by cells. breathing rate and heart rate will increase to keep up with the demand of oxygen of your muscles and also in order to remove the larger amount of carbon dioxide that is being
