Explain why and how blood glucose is transported to exercising muscle when blood glucose level is not high enough to stimulate insulin release.

Explain why and how blood glucose is transported to exercising muscle when blood glucose level is not high enough to stimulate insulin release. In other word, explain how blood glucose is transported to exercising muscle without relying on insulin (1.5 Points).
Explain the difference between respiratory exchange ratio (RER) and respiratory quotient (RQ) (1 Point).