<span>Answer:
Respiration is a very important process that happens in all living things. It is the way in which our bodies release energy from the food we eat.
When your hand is above your head, the flow of blood is reduced. This means the
supply of glucose and oxygen to the cells is limited, they respire less, and release less
energy. Therefore, the cells get tired more quickly and ache more readily. Pupils may
also account for their results by discussing anaerobic respiration.</span>
