Core Strength Beyond Crunches

The word core is widely used and little understood. It is often taken to mean the abdominal muscles, and core training has become synonymous with endless crunches. In reality, the core is a complex system that does far more than flex the spine, and training it properly produces benefits well beyond appearance.

The core can be thought of as a muscular cylinder around the trunk. At the front are the rectus abdominis, the so-called six-pack muscle, and the deeper transversus abdominis. At the sides are the internal and external obliques. At the back are the muscles along the spine, including the erector spinae and the deep multifidus. The diaphragm forms the top of the cylinder and the pelvic floor the base, and the muscles of the hips and buttocks connect the trunk to the legs.

The main job of this system is not to bend you forward but to stabilise your trunk, so that force can be transferred between your legs and arms. When you lift a box, throw a ball, climb stairs or even walk, the core muscles work to keep the spine steady. A well-trained core therefore improves everyday movement and athletic performance, and may help to reduce the risk of back pain, although the research suggests that core exercise is not uniquely superior to other types of exercise for back pain.

Before moving to exercises, it helps to understand two basic skills: breathing with the diaphragm and bracing the trunk. Both turn the core from a passive structure into an active one.

Diaphragmatic Breathing

Lie on your back with your knees bent, one hand on your chest and the other on your belly. Breathe in slowly through your nose, letting your belly and lower ribs expand, while your chest stays relatively still. Breathe out slowly. Practise for a minute or two, ideally once a day.

Bracing

Bracing means creating gentle tension around the entire trunk, as if you are about to be nudged in the stomach. It is different from sucking your belly in. Tighten your abdominal muscles gently, with the side and back muscles engaged as well, while breathing normally. Aim for about 30 per cent of maximum effort. This stiffens the spine and prepares the trunk to resist movement.

The first group of core exercises teaches the trunk to resist arching or sagging. They are among the safest and most effective, and they form the foundation of the programme.

The Dead Bug

Lie on your back with your arms pointing to the ceiling and your knees bent at right angles over your hips. Brace gently and press your lower back softly towards the floor. Slowly lower your right arm and left leg towards the floor, then return and swap sides. Move only as far as you can while keeping your back in contact with the floor. Aim for eight to ten repetitions on each side.

The Plank

Support yourself on your forearms and toes, with your body in a straight line from head to heels. Tighten your abdominals and buttocks, and breathe. Begin with 15 to 20 seconds, building up to 30 to 60. If this is too hard, start from your knees or with your hands on a raised surface. Stop when your hips sag.

Progressions

Make the dead bug harder by straightening your legs, holding a light weight, or reducing the support of your arms. Progress the plank by raising a foot or arm, by moving your elbows forwards slightly to lengthen the lever, or by holding a plank on your hands with your body in a long line. Do not progress if technique deteriorates.

The trunk must also resist twisting and sideways bending, which happens whenever you carry something heavy in one hand, walk on uneven ground or swing a racquet. The following exercises train these abilities.

The Bird Dog

From hands and knees, extend the opposite arm and leg, keeping the trunk level, as if a glass of water were balanced on your back. Hold for three to five seconds and return. Repeat eight times on each side.

The Side Plank

Lie on your side with your forearm beneath your shoulder and knees bent. Lift your hips so your body forms a line from knees to head. Hold for 15 to 30 seconds on each side. To progress, straighten your legs, with feet stacked or staggered.

The Pallof Press

Attach a resistance band to a secure anchor at chest height. Stand side-on, holding the band with both hands at your chest. Press your hands straight out in front of you, resist the pull of the band that wants to rotate you, and return. Do eight to ten repetitions each side. The movement is small, but the demand on the trunk is considerable.

The best core training often does not look like core training at all. Exercises that challenge the whole body train the trunk in the way it is used in life.

Carries are a good example. In a suitcase carry, you hold a weight, such as a dumbbell or a full shopping bag, in one hand and walk with your body upright, resisting the temptation to lean. This trains the obliques and the deep muscles of the spine. In a farmer's carry, you hold a weight in each hand. In a front-loaded carry, you hold a weight at your chest. Walk for 20 to 40 metres, rest and repeat.

Squats, deadlifts, overhead presses, rows and press-ups are all, in effect, core exercises, because the trunk must stay rigid as the limbs push or pull. This is why a well-rounded strength programme builds core strength alongside the rest of the body.

If you want a dynamic exercise, include rotational movements using light loads, such as controlled wood chops with a band or cable, or medicine ball throws, once you have built good stability. Crunches and sit-ups are not forbidden, and they can train the abdominal muscles, but they are not essential.

Core training does not need to be time-consuming. A short routine two or three times a week, combined with a good general strength programme, is enough for most people.

A sample session might include three sets each of the dead bug, the bird dog and the side plank, with a plank to finish and a suitcase carry. Allow about 15 minutes. Begin with one or two sets and build up. Increase difficulty by lengthening holds, making the exercise harder, or adding load, but only when technique is secure.

If you are pregnant, discuss exercise with your midwife. Gentle strengthening and pelvic floor work are generally encouraged, but advice on positions, such as lying flat on the back later in pregnancy, varies, so seek guidance. After childbirth, a gap between the abdominal muscles, called diastasis recti, is common and often narrows on its own. If you are concerned, or if you have leakage, pain or a bulge, ask for a referral to a women's health physiotherapist.

If you have back pain, the exercises in this ebook are generally suitable once the acute phase has passed, but start gently and speak to a physiotherapist if symptoms persist. Remember that core strength is one part of a wider picture: general activity, good sleep and a healthy lifestyle matter as much.