Young and old, male and female, strong and healthy or weak and out of shape, everyone can benefit from yoga. The only pre-requisite is the desire to lead a fuller and healthier life.
There's no competitive aspect to yoga. The right mentality, concentration and effort put into getting the postures right are all that count. It's all about strength of will and perseverance: absolutely anyone will get their postures right eventually, however difficult they may seem at first.
What's more, when you've worked hard and you do get it right, you get the most incredible feeling of self-fulfillment which carries over into every aspect of your life. You feel as if you can achieve anything.