There are many people over 40 who have succeeded in keeping fit. You can also be one of them if you have the correct attitude towards your workout program. Have a definite set of goals that you are looking to achieve at the end of your workout. This is very important for people who are over 40 as it helps to keep them motivated. It is important that you know your body composition, flexibility and muscular strength before you begin any exercise.  

It is necessary to ensure that you emphasize on technique and form whilst lifting weights. This does not mean that you cannot challenge yourself while lifting weights; it actually means that you should lift weights using good technique and form to avoid harm. The best way to do this is to avoid using momentum while lifting weights but instead you should use your muscle power. Lower and lift the weights in a controlled and steady manner.