Stretching should be included as part of any routine, whether you play sports, work out at home, in the gym or in the park.

During exercise, muscles contract and shorten as they are being asked to work hard.

When muscles shorten, tension builds up, and this can have a significant effect on your posture, flexibility and mobility.

Certain areas of the body become tighter as a result of exercise, mainly the thighs, hamstrings, calves and the outside of the legs. It is very important to stretch these muscles regularly as poor flexibility can lead to more serious problems such as back pain.

Even if you lead a sedentary lifestyle, your muscles will become tighter, your joints will not move freely and you will feel stiff through inactivity.

For a lot of us, work involves sitting at a desk for up to eight hours a day, putting added strain on your lower back and creating a rounding of the shoulders, drawing your posture forwards. It is also vital to keep yourself active as you get older to keep your joints supple and to promote mobility. Activities should include everyday tasks such as gardening and housework.

Most commonly, people tend to stretch before and after exercise, but stretching can be performed at any time of the day.

You don't really need to stretch before exercise but it is very important to warm up. Types of movements you should perform are those that replicate the activity you are about to embark on.

For example, to prepare yourself for a game of football, all different types of kicking actions with and without the ball and jumping exercises should be included in your warm-up routine. You should, however, include stretching at the end of your workout, as this will prevent next-day muscle pain and reduce stiffness. You should be aiming to stretch each muscle for around ten seconds but in order to increase mobility, aim to stretch each muscle for 20-60 seconds.

When stretching, focus on the big muscle groups, such as the thighs, hamstrings, chest, upper and lower back and the calves. This will not only promote flexibility but also retain your postural balance.

Christian Fox is a personal trainer, Sports massage therapist and nutritional advisor working in and around York. Phone 07711 871170 for your free session.