The "core" is a common term used to refer to the middle section of the body between the lower part of the rib cage and the hips. There are 29 muscles in this area including the pelvis, spine, lower back, hips and trunk. Core muscles maintain body stability and transfer power from the legs to the upper body and vice-versa. Core strength training improves overall body functional power, balance, posture and may help reduce the risk of injury. By understanding and applying the science related to the core muscle stability and strength, you can develop more effective running mechanics and avoid lower back pain and other physical challenges.
Why your Core Muscles are Important
Your core muscles are essential to your overall physical fitness because your body is an interconnected system. For example, tightness in your hamstrings can cause pain in your lower back and a foot injury can lead to pain in your hip. The core muscles help stabilize the entire body and transfer force from the lower body to the upper body. They are also a part of the "kinetic chain," which is a sequence of events that allows each part of the body to be activated at the optimal time and sequence to execute a given movement. A good example of the kinetic chain is how a soccer player uses their whole body in sequence to kick a soccer ball. In running, the example would be how the left arm moves in sequence and time with the right leg to transfer forces, stay balanced and to run effectively and efficiently. To ensure the optimal functioning of all parts of your body, you need to make sure that your core is strong, stable and flexible.
Research has discovered significant links between core strength and speed in distance runners. Subjects who completed a six-week core strength training program of back extensions, hip raises, Russian twists and abdominal crunches on a stability ball experienced a statistically significant improvement in their 5km run times versus a control group that did not engage in core strengthening.(1) This study also found that lower leg stability and running kinetics remained unchanged for all of the runners involved, illustrating the importance of training the core in combination with the lower body to promote overall running performance. Another study illustrated the interconnected nature of the body by illustrating that tennis players who had a proper knee bend and body position were less likely to sustain an elbow or shoulder injury.(2)
Improve Your Performance
When developing your core muscles, you need to focus on both muscle strength and muscle endurance. This is because these core stability muscles are used in most daily activities, not just while running. If your core muscles are not well developed, they will become easily fatigued and you will be at greater risk of instability, injury, and poor running mechanics. When you are designing a program to build your core, make sure it includes exercises that build both the strength (fewer reps and more resistance) and endurance (more reps and less resistance) of your core muscles. Always start with less resistance and progress slowly to higher resistance levels.
You also need to keep in mind that because the whole body is connected, you need to activate your core in a way that also engages the nearby lower and upper body muscles so that the whole system learns to work together. Sample activities that will create this dynamic are hip raises while you lie on your back, superman raises (alternate legs and arms being lifted while you lie on your stomach), and side and front planks. For runners, these exercises are great because they relieve stress on the hamstrings, lower back and knees while still strengthening the core muscles. They will also simultaneously develop the strength and flexibility that is needed in the core muscles because keeping the core strong but fluid and open is important for energy transfer. Make sure you have a fitness professional show you how to do these exercises properly to maximize the training effect and minimize your risk of injury.
Because core training puts stress on the spine, it is critical that you learn how to do the exercises properly. You should always focus on balance and control while training the core muscles and make sure a professional (certified physical trainer, kinesiologist, or your athletic/physio therapist) teaches you proper technique before you practice on your own. In particular, if you have a history of back pain, make sure you consult a physiotherapist of chiropractor before beginning a core strengthening program to make sure there are no underlying causes of your back pain or weakness. For an excellent core strength program that is specifically designed for people who are rehabilitating from back injuries, go look into Solid to the Core at www.solidtothecore.ca.
Developing strength in the core of the body is critical for most sporting movements, especially running. To get the benefits, core stability and strengthening exercises must be performed regularly and consistently – just like you need to run regularly and consistently.
To establish a fluid and strong set of core muscles, follow these tips:
• Do core exercises at least three times a week
• Focus on exercises that engage your core muscles but also work the surrounding upper body and lower body muscles
• Build up slowly if you are just beginning to exercise your core muscles
• Be aware of your spine alignment at all times and ensure that you are engaging your core muscles and maintain good posture (avoid sagging or slumping).
For more information on core stability and back health refer to the work of Dr. Stuart McGill, a spine biomechanist, from the University of Waterloo, which can be found at www.backfitpro.com/ultbackbook.htm.
Sato K, Mokha M. (2009). Does core strength training influence running kinetics, lower-extremity stability and 5000-M performance in runners? Journal of Strength and Conditioning Research 23(1): 133-140.
2 Kiebler WB, Press J, Sciascia A. (2006). The role of core stability in athletic function. Sports Med 36(3): 189-198.
Greg Wells Ph.D. (www.drgregwells.com, @drgregwells) is an Assistant Professor at the University of Toronto in the Faculties of Medicine and Kinesiology. He was the sport science analyst for the Olympic Broadcast Consortium during the 2010 and 2012 Games, and is the author of Superbodies: Peak Performance Secrets from the World's Best Athletes. Jessica Caterini is a member of the Human Physiology Research Unit in the Faculty of Kinesiology at the University of Toronto.