rest is an important part of recuperation and healing. balance is key, because a dormant metabolism does little to help. mild activity and spaced out small meals keeps the metabolism from going too low to be helpful. regular activity like cycling helps to boost your immune system, so you will be less likely to get sick. when I bike commuted I was clearly the healthiest person in the office. my colleagues around me would call in sick while I continued cycling through winter strong as an ox. they were baffled. I was not.