What physiological changes from exercise are needed to maintain homeostasis?
When the body is under stress (exercising) it releases stress hormones such as epinephrine and norepinephrine. These hormones activate the sympathetic nervous system bringing about the physiological changes you mentioned. The body will also produce sweat to maintain temperature. The respiratory rate changes because as you use up energy in the form of ATP, you will be depleting your body of oxygen (since it is the ultimate oxygen receptor at the end of the electron transport chain, used to make ATP). So, as you use up more oxygen, you need to supply your cells of more oxygen, so your red blood cells will go to the lungs to get more oxygen and release more CO2. That also brings up the pH homeostasis of the blood. These are all long and involved processes, but I hope that me bringing up those few helped you.