Exercise-it does a body good. We all know it, even when our lives and schedules get the better of us. A good cardiovascular workout helps us reduce the risk of a variety of diseases and allows us to maintain a healthy weight and a strong heart, but many doctors also believe that vigorous exercise also boosts the healthy appearance of skin.

So how does a sweat session help us get glowing skin and how much exercise is enough? First, let's look at the three key factors that improve the look of...