Core training: exercises for the front, back and sides, properly structured

You are resting on your forearms, the clock is running, and after half a minute your abdominal muscles start to tremble. Your pelvis sinks towards the floor, but you hold on anyway, because only the seconds seem to count. This is how many people experience the plank. Good core training works differently: it treats the core as a system made up of the front, back and sides, pays attention to a clean position and increases the load in clear stages. Here you will find out which exercises it includes, how to perform them correctly and progress them step by step, and what trainers look out for when giving instructions.

The core as a system: three sides, many muscles

Core exercises can be assigned to three areas: the front, the back and the lateral core muscles. The muscles primarily involved are the straight abdominal muscle (rectus abdominis), the internal and external obliques (obliquus internus and externus), the transverse abdominal muscle (transversus abdominis), the back extensor (erector spinae), the square lumbar muscle (quadratus lumborum) and the hip flexor iliopsoas. Nothing is worked in isolation, as several core muscles always work together. If only one leg or one arm moves, the activation of the obliques and the quadratus lumborum, for example, increases. In more difficult variations, the hip flexors, hip extensors, knee flexors and the chest, back and shoulder muscles are also heavily involved. Afterwards, suitable length training is recommended.

Core stability here means that the core and spine are stabilised during every exercise rather than moved. The muscles work statically, that is isometrically without movement, or with minimal, controlled movement. Movement in the spine under simultaneous load is deliberately avoided: the arms and legs move while the core holds steady. If your main focus is on appearance, the topic of ab training for a visible six-pack is the right complement.

Clean technique: basic rules for every core exercise

These rules apply to all variations:

• Natural position: The head stays in line with the spine, the shoulders are low and back, and the wrists are stabilised.
• Spine and pelvis: They keep their anatomically optimal position with slight natural curves. For many exercises, the explicit rule is: no arched lower back.
• Tension first, then movement: Consciously brace your core before your arms or legs move.
• Breathing: Keep breathing normally. Your breathing rhythm does not have to match the rhythm of the movement.
• Tempo: Move slowly and with control. In variations with movement, you usually hold each position for about one second.
• Limit: Only progress as far as correct execution remains possible.

The aim is to fatigue the muscle as much as possible. So seek out the resistance instead of avoiding it. Momentum takes work away from the muscle, and explosive movements drastically increase the risk of injury. High movement quality therefore has top priority.

Front of the core: from the kneeling plank to leg and arm movements

The exercises follow an increasing level of difficulty. The order is at the same time the path of progression, in other words the step-by-step increase:

1. Kneeling plank: Elbows directly below the shoulders, upper body in a straight line, an angle of about 140 to 150 degrees between thighs and upper body. The distance between the knees and the elbows controls the difficulty via leverage.
2. Kneeling plank with movement: First you straighten both knees at the same time into the classic plank and back again, later one leg after the other, without any rotation in the spine and pelvis.
3. Plank: The whole body forms a straight line, and the abdominal, leg and upper body muscles are active.
4. Dead bug: Lying on your back, your arms and legs are extended and slightly raised, your head by no more than 5 centimetres. Alternately, you bend one leg at the hip and knee to 90 degrees and bring the opposite arm, extended, into a vertical position.
5. Mountain climber: In a plank position on your hands, you alternately bend one leg at the hip to about 90 degrees and only lightly touch the floor. Your spine and head do not move. Advanced exercisers also draw an imaginary square with the foot.
6. Plank with leg and arm movement: At first only one leg at a time lifts slightly, and in the final stage the opposite arm lifts at the same time. This requires a high level of concentration and is very advanced.

After the dead bug, slight muscle soreness in the neck flexors is possible over the following days. If even the first stage is too difficult or painful, a standing plank against the wall replaces the kneeling plank. The load is then regulated by the distance between your feet and the wall.

Back of the core: bridge, swimmer and reverse plank

The back starts with the bridge. Knees to shoulders form a line, the feet are hip-width apart below the knees, the abdominal, leg and gluteal muscles are active, and an arched lower back must be avoided. Imagine you want to push the floor away from you with your feet. In addition to the front of the core, the gluteal muscles work hard, while the hamstrings at the back of the thigh should only play a minor role. The alignment of the legs is often neglected, resulting in a knock-kneed position.

• Bridge with leg movement: Alternately straighten one leg and hold for about one second, in the next stage for 10 seconds, with 2 to 3 seconds in the starting position in between.
• Swimmer: Lying on your front, your hands are under your slightly raised head and your gaze is directed downwards. One leg lifts slightly, and the opposite arm is extended but not raised. The movement remains very short, without rotation and without an arched lower back.
• Reverse plank: Elbows directly below the shoulders, the body in a straight line, gaze upwards, neck long. The gluteal, shoulder and back muscles work hard. This is followed by the reverse mountain climber and variations with leg movement for advanced exercisers, in which the pelvis must not sink between repetitions.

If the bridge is too difficult or painful, the swimmer replaces it, with only the arm being moved.

Side of the core: the side plank in stages

The side starts with the kneeling side plank with movement. You support yourself on your forearm, with the elbow directly below the shoulder and the hips and knees bent. Now the thigh lifts as you extend your hip until knee, hip and shoulder form a line. The hip moves forwards, not upwards, and the spine and head stay still.

• Held variations: First you hold the end position for 10 seconds at a time with 2 to 3 seconds of rest, then continuously.
• Side-lying leg raise: The straight legs are lifted slightly and held isometrically, without bending the lumbar or cervical spine sideways. If you do not yet have the strength for the minimum duration of 30 seconds, split it into sections of 10 seconds with 2 to 3 seconds of rest.
• Roll over: From lying on your back with arms and legs extended and slightly raised, the whole body rolls as one unit into a side-lying position and back again. Only in the thoracic spine is a small amount of flexion or rotation allowed.
• Side plank: Feet, knees, hips and shoulders in a line, the top leg in front, and the top shoulder does not drop forwards. In the final stages for advanced exercisers, one leg also moves, in some cases the top arm as well, and the pelvis must not sink between repetitions.

With shoulder problems, the free hand can stabilise the loaded shoulder. If the first stage is too difficult or painful, a standing side plank against the wall replaces it.

How to progress: time under tension and progression

With core exercises, what counts is the time under tension, not the number of repetitions. The target range is 30 to 100 seconds. If you can perform an exercise correctly for longer than 100 seconds, you move on to the next progression, that is, the next more difficult stage for the same side. Until then, you try to beat the time you achieved in your next training session. So it is worth recording it in your training plan. Progression comes from leverage, stability through the points of support, the planes of movement and duration, but never at the expense of movement quality.

On each side, the first three stages form the basis: the kneeling plank with its movement variations, the bridge with and without leg movement, and the kneeling side plank. They are generally manageable for beginners and people with back problems too, while advanced exercisers can start with further variations. Choose the same number of exercises for all three sides and do not overload the core muscles: the exercises can replace or supplement existing core exercises in the training plan, although supplementing is better suited to people with excellent fitness and no complaints.

Instruction and caution: what trainers look out for

On the floor, freedom of movement is considerably greater than on guided strength machines, which is why precise instruction and correction are essential. First, the complete movement is demonstrated and explained in its individual phases. During the exercise, the trainer stands discreetly, not directly in front of or behind the person, actively gives feedback on the position and asks how it feels.

With complaints of any kind, from non-specific symptoms to injuries and operations, an exercise is adapted immediately or replaced by a pain-free one. Anyone who can hardly lie down because of severe movement restrictions needs other exercises, for example on machines. Back pain should be checked by a doctor. What the back fundamentally needs is explained in the article Back pain: stretching or strength training.

Particular caution is needed with cardiovascular problems. During purely static strength exercise, both the upper (systolic) and the lower (diastolic) blood pressure rise significantly. Static loads above 20 percent of the maximum possible contraction force in particular raise blood pressure, while heart rate increases only slightly and stroke volume, that is, the amount of blood ejected with each heartbeat, stays the same or even decreases. This is known as a pressure load on the heart. Anyone affected should have static core training cleared by a doctor beforehand.

Course tip from update Akademie: If you want not only to do core exercises yourself but also to teach them properly to others, you need sound knowledge. In the Fitness- und Bewegungstrainer Basic (fitness and movement trainer) course, training theory as well as anatomy and physiology are part of the programme, complemented by a dedicated section on advanced core exercises, from the exercise portfolio to instruction.

Frequently asked questions about core training and core exercises

How long should you hold a plank?

For core exercises, the time under tension is 30 to 100 seconds. What matters is that the position stays clean the whole time: elbows directly below the shoulders, the whole body in a straight line, the abdominal muscles consciously braced. If you can hold the plank correctly for longer than 100 seconds, do not keep extending the time but move on to the next, more difficult variation.

Which core exercises are good for beginners?

The first three variations on each side serve as an introduction: the kneeling plank, including with movement, the bridge with and without leg movement, and the kneeling side plank. This foundation is generally manageable for beginners too. If it is too difficult or painful, variations performed standing against the wall or the swimmer with arm movement only can help.

How do you progress core exercises correctly?

Progression comes from leverage, stability through the points of support, the planes of movement and duration. First, you build up the holding time within the range of 30 to 100 seconds. If you can manage more than 100 seconds correctly, you move on to the next variation, for example from the kneeling plank to the classic plank. The load only increases as far as the execution stays clean.

Is core training a good idea if you have back pain?

Back pain should first be checked by a doctor. For training, the rule is: if there are complaints, core exercises are adapted immediately or replaced by pain-free variations. The basic variations on each side are generally considered manageable for people with back problems too, and the spine remains stabilised throughout. Anyone who can hardly lie down because of severe movement restrictions switches to other exercises, for example on machines.

Conclusion

Good core training is not an endurance contest. It distributes the work across the front, back and sides, keeps the spine stable and increases the load in clear stages. If you perform every variation cleanly, aim for 30 to 100 seconds of time under tension and only then move on to the next stage, you build up your training in a clear and logical way. When there are complaints, you adapt instead of gritting your teeth, and anyone with cardiovascular problems should have static exercises cleared by a doctor beforehand.