Noticeable physical changes that occur during exercise include

the muscles need extra energy as: the breathing rate and volume of every breath increments to carry more oxygen into the body and eliminate the carbon dioxide delivered. the pulse increments, to flexibly the muscles with additional oxygen and eliminate the carbon dioxide delivered.

Explanation:

it keeps oxygen levels low throughout the body

answer:

explanation: in what sense? do you mean like forget about them after losing their connection or are we talking about a mother forgetting her child in a car or store?

as for the child one, i have no idea. probably a very high level of stress and or tiredness.

as for the emotional connection loss one, if you are trying to get over somebody and forget them, you don't. atleast not completely yet and certaintly not immediately. it takes time. patience and alot of distraction. it gets easier every day. have a good support system. a best friend or parent perhaps. someone who will be there for you and you get through this and who will listen. also lots of water and stretching and deep breaths if you really start to get down.