Thanks to numerous studies and experiments it has been discovered that glucose is an important factor in muscle contraction and that glucose metabolism is essential for life.(3) In order for glucose to be absorbed by muscle cells must be transported via the GLUT transporter 4, an integral membrane protein that translocates from the interior of the cell to the plasma membrane in response to muscle contraction and elevated blood glucose levels.(textbook)When muscle cells are subjected with long periods of intense physical activity their need for glucose as a form of energy increases dramatically. Using experiments focusing on glucose concentration and blood flow from the bloodstream to muscle cells, it was found that blood glucose accounted for 40% of oxidative metabolism when glucose stored by glycogen in muscle cells was low. GLUT4 is essential for glucose absorption and can be divided into three phases; glucose delivery, glucose transport and glucose metabolism. Glucose is delivered to cells through the bloodstream; an increase in blood flow, perhaps due to physical activity, increases its quantity ...