Core training

Here is a reflection of core stability training based on work that I have recently reviewed. I have used references infrequently and is this reflection is meant to be a written example of my thoughts on the topic. I have attempted to refer to scientific and professional literature where possible but this was never intended to be of publishable standard. Please take the ideas and reflect on them for yourself and see if you agree or disagree and more importantly how you may develop your thinking about core stability and apply this in your own coaching/training.

A popular term within the health fitness industry that holds a lot of prestige and helps to ‘sell’ personal training is core strength/stability. Many courses, workshops and qualifications are sold on the basis of developing a trainer’s competence in delivering expertly prescribed and cutting edge core training interventions. However, I believe that an understanding of the underlying scientific principles, the structure and function of the human body facilitates a more evidence based approach to coaching ‘core strength/stability. The current article will aim to define core stability and discuss a reconceptualised approach to thinking about and coaching core strength/stability.

Stability when applied to the ‘core region’ refers to the ability of the spinal system to resist perturbations (Behm, Drinkwater, Willardson, & Cowley, 2010). Consequently, core stability implies the ability to maintain anatomical neutral zones within a natural range of motion or physiological limits. This includes maintaining stability when forces are applied that attempt to disturb the neutral position of the spine. Therefore, the goal of any core stability programme should be to develop the ability to resist perturbative forces specific to the individual’s needs. For example, a rugby player would have comparatively different needs to an elderly individual aiming to ‘move better and move more’. An athlete may need to consider progressive methods of overloading the adaptive processes of the body.

The body is a system of interlinked segments that interact and mutually affect the position and function of each level. This is why the human body is commonly referred to as a kinetic chain. A causative effect can be identified by the coach as ‘bottom up’ or ‘top down’. A bottom up effect refers to a tightness or weakness of a ‘lower’ body part affecting the position or function of a joint that is higher up in the chain. For example, restricted range of motion in the ankle may result in compensations in the form of tibial internal rotation. This will affect knee positioning due to the interactive effect of tibial rotation on the femur via the knee joint. The resulting internal rotation of the femur and knee joint valgus (knees moving inwards: ‘knocked knee position’) affects both hip external rotator (e.g gluteus medius) activation and muscle resting length which affects the ability to externally rotate the femur and maintain knee stability. The inward movement of the knee also predisposes the individual to injury, especially when load is added in the form of more explosive movements or resistance training.

A top down approach refers to a muscle or joint higher up affecting the position and/or function of a joint lower down in the kinetic chain. For example, if hip external rotators such as the gluteus medius are weak or lack the timing and coordination this will again affect the position and function of the knee. Internal rotation and knee valgus will be the likely result decreasing knee stability and increasing the risk of injury. Imbalance between left and right ankle, knee or hip strength or range of motion will also result in hip angle changes and consequently disturb the position of spinal vertebrae. This necessitates corrective interventions as a means of facilitating correct positioning of the spine before attempting to increase the ability to resist perturbations (increased core stability). Corrective interventions may take the form of stretching tight muscles (e.g. the gastrocnemius and soleus from the above example of ankle restriction), strengthening in isolation (e.g. gluteus medius in the above hip example) and integrating this strength into specific movements to develop motor patterns, timing and coordination.

Once correct dynamic spinal positioning has been achieved, interventions can begin to emphasise the overloading of these correct positions/movements by using resistance training (to increase stability to resistive forces) and/or more explosive exercises (ballistics/plyometrics) to improve the ability to maintain correct spinal positioning during more specific and perturbative movements.

Resistance training can take the form of progressively overloaded variations of the deadlifts and squat (Martuscello et al., 2013). If performed with the correct positioning and intention to maintain form, these exercises will challenge the ability to maintain spinal neutral zones under progressively heavier loads. Addition of ballistic lifts such as the clean, jerk and snatch will challenge the body to stabilise a large load very quickly during explosive, heavy and somewhat unstable movements (Martuscello et al., 2013). The addition of unstable loads, such as those seen in ‘strongman’ competition (e.g. water filled logs etc) further challenges the ability to maintain stability against perturbative forces (Fletcher, 2014). Finally, including plyometrics in the training programme will challenge the ability to stabilise spinal neutral zones even further using sport-specific movements that can be progressed or regressed as required. Progressions can take the form of increasing box height during drop jumps, directional changes, landing and jumping using one foot instead of two, increasing the volume of work and increasing the explosive intent during the movement.

Summary

Core stability training refers to the ability to resist spinal perturbation and maintain natural spinal neutral zones between vertebrae. As the kinetic chain is interlinked tightness, weaknesses or lack of motor control at one point in this chain will affect joint position and function elsewhere in the chain. Therefore, a coach must first establish good position through corrective interventions before attempting to develop the ability to resist perturbations. Athletes can effectively use resistance training exercises such as deadlifts, squats, cleans, jerks, snatches, strongman lifts (e.g. log lifts) and plyometrics as a means of facilitating both core stability and performance enhancement.

References

  • Behm, D. G., Drinkwater, E. J., Willardson, J. M., & Cowley, P. M. (2010). Canadian Society for Exercise Physiology position stand: The use of instability to train the core in athletic and nonathletic conditioning. Appl Physiol Nutr Metab, 35(1), 109-112. doi: 10.1139/h09-128
  • Fletcher, I. (2014). Myths and reality: training the torso. Professional strength and conditioning(33), 25-30
  • Martuscello, J. M., Nuzzo, J. L., Ashley, C. D., Campbell, B. I., Orriola, J. J., & Mayer, J. M. (2013). Systematic review of core muscle activity during physical fitness exercises. The Journal of Strength & Conditioning Research, 27(6), 1684-1698.