Fitness instructors laud the squat as being among the best strengthening moves for the lower body, with one recent American survey of more than 36,000 gym trainers naming it as the most effective exercise for toning muscles and improving balance.

Done properly, this flexing of the hips, knees and ankles will lengthen and strengthen the spine and simultaneously will work all the main muscles in the legs - including hamstrings, quadriceps, gluteal and calf muscles - as well as the trunk and lower back muscles that help to stabilise the body.

A less enviable accolade, though, is that the squat is often performed with appallingly bad technique. Among the most common errors is lowering the legs beyond a 90-degree angle, causing the bottom to stick out and the spine to tilt in the lumbar region, eventually leading to postural weakness. Arching the lower back so that the head and neck are crunched back can also cause tightening in every part of the body from the neck down. Studies have shown that badly executed squats can cause knee and back problems over time.

Before you move on to using weights, try to master the basic bodyweight squat, as follows:

1. Stand with feet almost shoulder-width apart. Make sure that your neck is not tense, try lengthening your torso while retaining the spine's natural S-shape.

2. Contract your abdominal muscles and breathe in. Start to release your knees until they are over your toes and your thighs are parallel with the ground. Keep your heels on the ground and the weight over the back of the foot rather than the toes.

3. Keep your back straight and hold your arms out in front of you for balance. Try to keep your tongue on the roof of your mouth to activate the neck's stabiliser muscles.

4. Breathe out and press through the heels to return to the start position. Repeat 20-30 times.

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