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What Is “A Strong Body”? - with Elizabeth Cordle
What Is “A Strong Body”? - with Elizabeth Cordle


Having a ‘strong body’ is a term that’s often thrown around in fitness and health circles, but what does it really mean? We sat down with Elizabeth Cordle, chartered physiotherapist and founder of, to delve deeper into the subject and answer questions that you might have about achieving a ‘strong body’. From muscles and exercises to diet and general health, we cover everything you need to know about what it means to have a truly strong body.


1. What are the best exercises to strengthen my core?

When considering the best exercises to strengthen the core it is important to first think about what the ‘core’ is. 

Our muscles are made of muscle fibres. There are two types of muscle fibre in the muscles we use to exercise the body. Fast twitch muscle fibres work at a high level for a short period of time and give us movement and power. Slow twitch muscle fibres work at a low level for a long period of time and give us stability and endurance. 

Every muscle has a percentage of fast twitch and slow twitch fibres. However, depending upon the percentage of these muscle fibres in each muscle, a muscle is either predominantly a movement muscle or a stability muscle. So, when we are thinking ‘core’ we are thinking of the stability muscles that sit very close to the skeleton, holding the bones together, giving stability and endurance. 

There are four key ‘core’ muscles. The serratus anterior of the shoulder blade, the pelvic floor, the glutes medius and the inside quadriceps (VMO) muscle. 

Therefore exercises which engage and activate and strengthen these key core muscles is the best place to start: 

Shoulder blade setting 

In sitting, gently pull the bottom of your shoulder blades down and in towards the small of your back. Hold gently for 10 seconds and repeat regularly throughout your day.

Pelvic floor in lying 

Lie on your back with your knees bent and feet flat. Place one hand on your tummy to feel yourself breathing and the other hand 1cm in and down from the front side pelvic bone. Breathe. Gently pull up the pelvic floor and hold for five breaths. Repeat X 10. Repeat once a day.

Glute Medius-Clam 

Lie on your side with your legs together. Bend your knees to 90° and have your feet, bottom and back in line as if against the wall. Rotate your pelvis forwards then, keeping your feet together, raise the top knee to the ceiling while holding your pelvis still. Hold for three seconds and repeat x10 on each side.

Inner quadriceps-VMO

Sit on the edge of a chair. Straighten your right knee. Turn the foot out and keeping the knee straight, raise the foot off the floor by 10cm. Hold for 5 seconds and relax. Repeat x10. 

The exercises above will engage the key core muscles. 

Try to activate these muscles when performing your normal workout. Pull down the shoulder blades, pull up the pelvic floor. Tighten the buttock (glutes) muscles and when squatting or lunging keep your foot facing forwards and your knee in line with your third toe to activate the VMO part of the quadriceps. 

Follow a free, six-week, progressive, functional core programme ‘The Corefulness Foundation’ at


2. What are the best ways to prevent injury from repetitive motion?

It is easier to think about this in the context of repetitive motion, for example, rowing. 

The best ways to prevent injury from the repetitive motion of rowing are to: 

1. Have a strong core.

2. Break down the motion and practice elements of it in a focused pattern with the core muscles engaged. For example; use a cable resistance machine to focus on upper body strength whilst engaging the core muscles. 

3. Strengthen the body in different motion patterns to the repetitive movement required – rowing requires you to pull with the arms and therefore strengthen in pushing patterns as well to even out body resistance. 

4. Regulate the amount of time spent on a repetitive movement – therefore cross-train on a bike or running to achieve cardio-vascular fitness to support the rowing.

5. When training on a repetitive motion vary the resistance, time and speed of training so that muscles strengthen through a variety of intensities. 


3. What lifestyle factors can help improve my physical health?

If you are wanting to improve your physical health and make lifestyle changes the most important thing is to make changes slowly, only change one or two things at a time and make your goals achievable. You don’t want to fall at the first hurdle otherwise you won’t get anywhere! 

Sleep is one of the most important factors affecting physical health. The body needs time to rest, repair and rejuvenate. Try to get at least 8 hours of sleep a night. 

A healthy balanced diet is vital to provide all the necessary nutrients to support the body both physically and mentally. Try to eat a wide variety of foods and reduce salt, sugars and fats. Try to cook using fresh ingredients. It may be helpful to seek advice from a nutritionist. 

Exercise is important for cardiovascular fitness, it may stimulate endorphins which are released from the brain and can improve mood. If you haven’t exercised for a while it is important to start slowly. Walking is an excellent form of exercise, try walking for 10 minutes and then work up to 20 minutes, three times a week. 


4. How can I reduce pain or stiffness in my joints?

Through my experience as a physiotherapist for the past 24 years, pain and stiffness in joints can occur for various reasons. In order to reduce pain and stiffness we need to work out the cause of the problem. 

In children, joint pain may well be a consequence of growth spurts. Long bones grow quickly meaning muscles can be tight because they haven’t lengthened at the same rate. Osgood Schlatters and Severs are two conditions which can produce joint pain in adolescents. 

People who either increase their level of exercise or change their type of exercise can experience joint pain and stiffness, generally due to muscles reacting to a change in activity. 

The menopause can cause joint pain and stiffness for some women. Joints have oestrogen receptors, so if oestrogen levels drop this can affect joints. 

Joint pain and stiffness can also be due to degenerative changes for example; Osteoarthritis or following injury or trauma. 

Referred pain from the spine can also cause joint pain. Nerves can get pinched and refer pain into different parts of the body. 

My advice would be that if regulating exercise or stretching doesn’t resolve joint pain, then seek medical advice to determine the reason for the pain.


5. What can I do to improve my posture?

Postural correction is reliant on good core muscles, repeated activation of those muscles to create muscle memory and good working ergonomics. 

My advice is to activate the serratus anterior, the stability muscles of the shoulder blade, by gently pulling the shoulder blade down and in towards your back pockets. Hold at a maximum of 40% of contraction (i.e. gently) and hold for at least 10 seconds. You will notice that by doing this you are unable to slump, therefore improving your sitting posture. 

You need to repeat this action regularly. If sitting at a computer, for example, every time you press ‘send’ on an email use this as a cue to pull the shoulder blades down. Think of other situations where you can make a cue for yourself to engage the pelvic floor in sitting and standing. 

Working through the free, six-week Corefulness Foundation on will teach you how to use muscles for correct sitting and standing posture. 

Correct seated ergonomics is vital. If your chair and desk are set up correctly then you should be able to sit comfortably and use minimal muscle activity to support yourself all day. It is important to move out of the seated position every 40 minutes to keep the body active. The Work Module on the Corefulness site is available to teach correct seated ergonomics and to run through a complete ergonomic workstation assessment. 


6. What exercises can help increase my flexibility?

Lack of flexibility often comes from tight muscles which can limit joint mobility. Muscles become tight for a reason. The most common reason is that they are compensating for weakness or tightness in the body e.g stiffness in the low back and a weak core and therefore posture is incorrect and muscles hold on. 

Muscles can also become tight following exercise and so a good stabilising and stretching routine is vital. See question 9 for stretches. 

To maintain spinal flexibility try these exercises: 

For the neck: 

Chin tucks

In sitting gently push your chin forwards, then tuck in and make a double chin. Repeat x10 and repeat 2 to 3 times a day.

Upper traps stretch 

In sitting gently take your nose down towards your armpit and hold for 40 seconds. Repeat x2 each way and repeat 3 to 4 times a day.

For the middle back: 

Thoracic rotations 

In sitting, cross your arms over your chest. Rotate to the right and bounce gently x10 then rotate to the left and bounce gently x10. Repeat three times in each direction. 

For the lower back: 

Low back rotations

Lie on your back with your knees bent and feet flat. Rotate your knees to the left and right. Repeat x10. And repeat twice a day.

Pelvic tilting

In sitting gently slump and round your back then sit up tall and arch your back. Repeat x10 and repeat 4 to 5 times a day.


7. How important is stretching before and after exercise?

Stretching is vital before and after exercise.

As a basic rule perform dynamic stretches prior to exercise and static stretches after exercise, try these:

Dynamic calf stretch

Stand on the edge of a step and raise up onto both tiptoes and then lower both heels below the edge of the step and feel the stretch at the back of the calf. Hold for a couple of seconds and repeat x30.

Dynamic Hamstring stretch 

Stand on the left leg and gently swing the right leg forward and backwards x20. Feel a gentle stretch at the back of the right leg. Repeat on the other side.

Dynamic quadriceps stretch

In standing, lift one heel to the bottom quickly and then repeat on the other side. Repeat x30.

Dynamic Hip flexor stretch 

In standing lunge forward with the left foot and place the right knee on the floor.

Flex forwards on the left knee to feel the stretch increase at the front of the right hip. Gently bounce into the movement and repeat x30.

For static stretches after exercise, try these: 

Calf stretch

In standing place the right foot in front of the left foot as if taking a step. Keep your feet facing forwards. Bend the right knee and feel a stretch up the back of the left calf. Hold for 40 seconds and repeat x2 on each side.

Hamstring stretch

Place your heel on the first step of the stairs. Keep the knee straight and gently push your bottom backwards and feel the stretch up the back of the thigh. Hold for 40 seconds and repeat x2 on each side.

Quadriceps stretch

In standing bend the right foot behind and hold the ankle. Keep your thighs parallel and tighten your buttocks to feel a stretch down the front of the right thigh. Hold for 40 seconds and repeat x2 on each side.

Hip flexor stretch 

In standing lunge forward with the right foot and place the left knee on the floor.

Flex forwards on the right knee to feel the stretch increase at the front of the left hip. Hold the stretch for 40 seconds and repeat x2, repeat twice.

Look at the Running Module on to find a series of stretching and warm-up exercises in the Evolve programmes. 


8. What are the 5 key sports equipment items that you keep in your KitBrix?

Being a physiotherapist, my KitBrix is full of practical items! 

- A water bottle which is designed for the intended sport, cycling, running or my son’s hockey goalkeeper water bottle with its long spout to use through the helmet grill! 

- Plenty of spare, warm, dry clothes to keep the body warm prior to an event and immediately afterwards. Muscles work best when they are warm. 

- Correct footwear with shock-absorbing insoles so that the body has the best chance of finishing the course. 

- Strapping tape to offload tight muscles and support tendons, ligaments and joints. 

- Massage oil to loosen off those tight muscles prior to or after an event.


Elizabeth Cordle is the founder of Corefulness®. During her 20 years of experience as a Chartered Physiotherapist, she has always sought to do more than just treat the symptoms, constantly looking for the root cause and ways to prevent injury in the first place.

The idea for Corefulness® is exactly that- a system which provides people with the knowledge and the tools to help themselves be fit, strong and healthy, in a revolutionary yet simple way. 

She has defined Corefulness® as ‘the use of core muscles through functional activities of the day to keep us healthy’ which simply refers to all the things we do in our day to function. 

Her ambition is to create a posture revolution across the globe, by providing people with the tools to help themselves. 


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