Many runners assume that, at the very least, ‘core training’ is something that they ‘should’ be doing – it’s generally accepted that we need to train our cores. So, when I sat down to look through the research on this topic, I expected there to be some reasonably clear consensus as to its benefits on performance and how to do it. Spoiler alert – it’s not that clear!
In this article, I’m going to give an overview of my exploration of this topic and then I’ll translate it as best as I can into some practical recommendations for your own training. At the end, you’ll find a video with a suggested series of exercises you can do at home.
What even is the core?
As I began to read through the research, I realised that it is not all that clear what our core even is – there is no standard agreement about which structures are included in it. There is no standard definition of ‘core strength’ or ‘core stability’, or even really any clarity over whether these are the same or different things. And there is no standard method of assessing it (1).
Definitions range from purely the muscles that attach to the lumbar spine, to the whole of the trunk including the spine, pelvis, shoulder girdle and all the trunk, shoulder and hip muscles. When talking about the core in relation to athletic potential, a more comprehensive definition is usually used compared to when we are talking about back pain rehabilitation.
To be clear – what I am discussing here is distinct from ‘core training’ as it’s used in the rehabilitation of low back pain – which is a whole other topic of debate in itself! Here I am talking about the use of core training in healthy athletes – and specifically in runners. Athletes have much greater demands placed on their bodies in terms of force and complexity of movement than the general population, so findings from back pain research can’t necessarily be extrapolated to sporting performance (1).
And what does it mean for it to be ‘strong’ and ‘stable’?
The most useful explanation I found was in a review by Wirth et al. (2) They describe core stabilisation as a combination of the strength of trunk muscles and the capacity of the nervous system to activate these muscles in a coordinated way.
How is this relevant to runners?
I think what we tend to imagine is that the core holds our trunk still while our legs move so that we don’t slop around all over the place.
What actually happens is a complex and coordinated activation and relaxation of various muscles of the trunk throughout the gait cycle to stop us falling over as our legs move rapidly over the ground. Staying upright and propelling ourselves forward while we run obviously does involve activity of our ‘core’ muscles. BUT it is more complex than simply locking everything down. The pelvis moves in all directions as we run – it tilts forward and back and side to side and it rotates left and right, and so does the torso. The pelvis and the torso also bend and twist relative to each other (3).
It seems unlikely that holding a plank or doing sit-ups will improve how our body manages this very specific kind of dynamic stability we have going on. It’s likely, however, that we can improve measures of strength through exercises that target different muscles or actions of the trunk.
Core stability training and running performance – what does the research say?
There is very little research that specifically addresses core training in runners. I could only find 3 studies that looked at this specifically.
One study (4) tested the ‘core endurance’ of runners by seeing how long they could hold a side plank, a back extension and a trunk flexion position. They then looked at what happened when they fatigued during a treadmill run. They found that, as they got tired, the runners tended to lean forwards more. We might have expected that the runners with better core endurance would be able to hold themselves in a more upright position, but in fact they found the opposite. The runners with better core endurance actually leaned forwards more as they got tired. I’m not sure what this means! But it does tell us that the relationship between core endurance measures and the ability to control trunk position in runners is not clear cut.
Two other studies looked at whether a core stability program would lead to improvements in running performance compared to a control group. Both studies used a 6-week core stability training program using gym balls. One (5) found that core stability improved, but performance measures did not. The other one (6) found that performance improved but core stability measures did not.
These were all very small studies and as you can see, there are not really any clear conclusions we can draw from these ones either!
What else does the research say?
The clearest indication, in relation to core training, that I discovered in my reading of the research, was that the most effective exercises in terms of activation of core muscles tend to be ground-based free weight exercises.
One trend that exists within the sphere of core stability is performing exercises on an unstable surface – so using Bosu balls or gym balls for example. If you perform the same exercise on a stable versus unstable surface, you will likely get more activation of core muscles in the unstable version. However – ground-based free weight exercises such as squats, deadlifts and Olympic lifts produce equal or higher activation of core muscles since you can employ much greater force, power, velocity and range of motion when you are standing on solid ground (7,8,9).
There is also good evidence that strength training can improve running performance (10)! So, if you have access to a gym, or if you are already doing this kind of strength work to support your running, then you probably don’t need to do any additional specialised ‘core training’ in order to strengthen your trunk muscles.
What if I don’t go to the gym?
If you don’t have access to a gym, and you’d like some exercises you can do at home with minimal equipment, I’ve put together a routine that you can try. This is not a routine that is ‘proven to improve your core strength and stability and help you run faster’. But I have tried to base it as much as I can on the research – bearing in mind that we have not yet discovered all the answers!
I’ve picked exercises that I think will help to strengthen muscles of the trunk as it flexes, extends, bends to the side, rotates and resists rotation. I’ve selected whole-body exercises over ones that attempt to isolate particular muscles or muscle groups (11). I’ve also picked exercises with good activation of the Glutes (Maximus and Medius) since we know these are important in runners. The Glute Max works to propel us forward and the Glute Med helps to stabilise the pelvis while we are balancing on one leg (12). I’ve also included exercises where we need to work to stabilise ourselves on one leg since this is more specific to the positions we get into when running.
Watch the video below for a demo of all the exercises including how you can make them harder or easier depending on your ability. Start at whatever level is appropriate for you and then try to progress it as it gets easier. You could complete this as a continuous circuit where you perform each exercise for 1 minute (or 30 seconds each side). Repeat the whole set once, twice or three times.
Final thoughts
My view is that maybe we need to think of strengthening our ‘core’ or trunk muscles as part of a comprehensive, whole body strengthening program and we needn’t necessarily single it out as something particularly special. It’s not clear in any case that ‘core stability training’ can directly translate into increased athletic performance (13). If you have the right equipment, or you can get to a gym, you can probably feel confident that you are strengthening your core with squats and deadlifts. Otherwise, give this routine a try and let me know what you think!
By Charlotte Softly.
You can read more about Charlotte and check her availability here.
References:
(1) Hibbs, Angela E., Thompson, Kevin G., French Duncan et al. (2008) Optimizing Performance by Improving Core Stability and Core Strength Sports Med 38(12):995-1008
(2) Wirth, K., Hartmann, H., Mickel, C. et al. (2017) Core Stability in Athletes: A Critical Analysis of Current Guidelines. Sports Med 47, 401–414
(3) Preece, Stephen J., Mason, Duncon & Bramah, Christopher (2016) The coordinated movement of the spine and pelvis during running. Hum Mov Sci, 45:110-118
(4) Koblbauer, Ian F. et al Kinematic changes during running-induced fatigue and relations with core endurance in novice runners (2013) J Sci & Med Sport xx:ppp-ppp
(5) Stanton, R., Reaburn, P.R. & Humphries B. (2004) The Effect of Short-Term Swiss Ball Training on Core Stability and Running Economy J Strength Cond Res 18(3):522–528
(6) Sato, K and Mokha, M. (2009) Does core strength training influence running kinetics, lower-extremity stability, and 5000-m performance in runners? J Strength Cond Res 23(1):133–140
(7) Behm, David G. & Anderson, Kenneth G. (2006) The role of instability with resistance training J Strength & Cond Res 20(3):716-722
(8) Nuzzo, James L., McCaulley,Grant O., Cormie, Prue et al. (2008) Trunk muscle activity during stability ball and free weight exercises J Strength Cond Res
(9) Martuscello et al (2013) Systematic Review of Core Muscle Activity During Physical Fitness Exercises, Journal of Strength and Conditioning Research: June 27(6):1684-1698
(10) Blagrove, R.C., Howatson, G. & Hayes, P.R. (2018) Effects of Strength Training on the Physiological Determinants of Middle- and Long-Distance Running Performance: A Systematic Review. Sports Med 48:1117–1149
(11) Gottschall, JS, Mills, J, & Hastings, B. (2013) Integration core exercises elicit greater muscle activation than isolation exercises. J Strength Cond Res 27(3):590–596
(12) https://www.running-physio.com/glutes2/ accessed 28/01/2021
(13) Prieske, Muehlbauer, Thomas & Granacher, Urs (2016) The Role of Trunk Muscle Strength for Physical Fitness and Athletic Performance in Trained Individuals: A Systematic Review and Meta-Analysis Sports Med 46:401–419