If you're fairly unfit, build up the intensity and frequency of exercise over a period of time. Do not go mad in the first few weeks, try and pace yourself and you will be surprised at how quick you can go from a beginners level into intermediate.
Our bodies are the homes of our souls. As long as they play house to our souls and allow us to exist in happy, healthy, harmonious ways they are utterly perfect. Vanity is but a whisper in the breeze and it is one that we should allow to bypass us.