Resistance training is all about keeping your muscles in good condition. This is essential if you want to achieve your maximum physical ability. The body is designed to perform in a certain standard way and so our muscles and muscle groups have evolved to match that standard. If, however, through injury or physical disability the body finds itself relying more on one group of muscles while using other muscles to a lessor degree then the 'standard' strain and pain can be experienced while at the same time reduced strength in other muscles can become problematic.
Some muscles do not get enough use to keep them strong even though they are essential for some functions that you need to do from time to time. In such cases, exercising can do much to help. For example; the effort required for transferring to and from a wheelchair is greatly reduced the stronger your muscles are. Resistance exercises can help to build muscular strength to ensure that you retain this type of dexterity and counter the natural effects of aging.
First and most importantly, since everyone is different and has different needs, get professional advice from your doctor or physical therapist before you start. You need to know which muscles and muscle group to exercise, which exercise you need to perform to achieve the best results, and you need to get advice on the level of activity that would be good for you.
So now you know what has to be done? Next you need a training program. You must decide the importance level that is appropriate for your exercises. Do you plan your days around your exercises or do you plan your exercises around your day? When you have answered this question you can draw up a training plan. This will set goals and allocate time and place criteria so that your exercises fit neatly into your daily life. Make sure that the time you allocate to them are not at times when you may be tired or interfere with other activities. Give yourself the best shot at keeping to the plan.
The USA's National Center on Physical Activity and Disability have some excellent 'Resistance Exercise Guidelines' for People with physical disabilities. You can read what they have to offer by following this link to Resistance Exercise Guidelines.
Don't forget that each Resistance Training exercise session must be started and ended with stretching exercises to warm up and to cool down.