Most physically disabled people realise the need to stay as fit as possible in order to get the most out of life. Fitness often equals health when you have a disability. That is not to say disabled people are not naturally healthy, but it is easier for them to suffer from certain health problems, once they become disabled.
For instance, having to sit for hours in a wheelchair can cause pressure sores, swollen feet and other problems. You will have to work really hard to keep yourself fit in order to prevent these problems. But there is more to it than meets the eye. Being healthy is not just a physical thing; it is also a mental and emotional one.