Core training

Training the "core" is an important consideration for most people wanting to improve fitness, recover after pregnancy and to generally be better equipped to deal with the stresses that life throws at us. As a result most gyms have Swiss Balls available for use and many also have "Wobble Boards" and Hard Foam Rollers to balance on. Until now it has been difficult to know when to workout on unstable surfaces like wobble boards and Swiss balls and when to simply stand on the hard stable gym floor.

The current issue of ACSM's Health and Fitness Journal (January/February 2008 Volume 12 Number 1) has an excellent analysis of when unstable surfaces help and when they hinder. Coming at the subject of core training from a medical and a scientific angle helps enormously. The chart to the right is an analysis of what exactly is in "The Core".

The analysis starts with:

• what exactly is "The Core"
• what exactly are you trying to achieve with "Core Training".

As it turns out the core muscles comprise much more than just the visible 6-pack muscles - the rectus abdominis. The core goes beyond just the abdominal muscles and the lower back which many have regarded as core muscles. The list of muscles gets rather long. Here is the ACSM view of core muscles after full consideration of human anatomy:

1. transversus abdominis
2. internal oblique abdominis
3. quadratus lumborum
4. external oblique abdominis
5. erector spinae
6. rectus abdominis
7. latissimus dorsi
8. rectus femoris
9. sartorius
10. iliacus
11. psoas (major and minor)
12. gluteus maximus
13. semimembranosus
14. semitendinosous
15. biceps femoris (long head)
16. multifidus
17. rotatores
18. intertransversalis
19. interspinalis

This is quite a list to which one could add a few more muscles. All of these muscles are working to some extent in all core related exercises. It turns out that "isolation" is just about impossible.

The big point from this ACSM article is the important perception about the results from training core muscles. Core exercise can emphasises one or more of :

• Endurance from core muscles
• Strength from core muscles
• Power from core muscles.

Looking at core exercise in terms of are you trying to improve endurance, strength or power means that the exercises used need to be different. If you want all three to improve then you'll need to train for endurance then strength and then power. Take a couple of weeks of exercise for your body to recover and then go around the exercise loop again but this time starting from a higher level.

Core Endure is important for everyone whether you are an older person recovering from a serious medical issue or a highly paid professional sports star. Unstable surfaces such as Swiss Balls, Bosu's and Wobble Boards all help in the development of core endurance. The technical term for an unstable surface such as a Swiss Ball is a "labile surface" Look at this article which has some nice pictures of abs exercises on a bench, on a Swiss ball and on a wobble board. However it also turns out that exactly where you place the Swiss ball makes a big difference to how hard the exercise is. Read this piece of research. It turns out that having the Swiss ball near your shoulders makes core exercise easier and having the ball at the low back makes it harder. This is important to know is you are just starting to move your core exercises onto a Swiss ball. Easier to start and then gradually increase the challenge.

Core Strength becomes important after the core muscles have sufficient endurance. To develop core strength you need to move your exercise to get off the Swiss ball, wobble board, etc and move to a stable surface i.e. the floor. However the important thing to know about this phase of core development is that one sided (unilateral) exercises become critical for strength development. Use dumbbells for one sided exercises with one or both feet firmly planted on the floor. An example would be a one-sided hip extension while holding a dumbbell (reasonably heavy) in one hand. This article reports research showing that you need a stable surface for strength development.

Core Power is the ability to generate a lot of force rapidly i.e. you can move heavy objects fast. For core power both feet have to be firmly planted and you are rotating while pushing a load well within your capabilities i.e. for core power the weight or resistance is less than you are capable of but you are moving the weight fast. For instance you might be pushing a cable row handle forward (or back) as fast as you can against a reasonable resistance.


There are many books on Core Performance. I really like the one opposite by Mark Verstegen which covers exercise from many angles.






There are also books which just describe Swiss ball exercises - of which there are a great number. The book by Goldenberg and Twist is aimed at a sports audience but is a good read for many people but it does not make any distinction between endurance, strength and power.