Core Strength Training

Core Strength Training

Brett Petersen, MS, CSCS – Petersen Performance Lab

Coaches, including myself, routinely recommend core strength training to improve athletic performance and reduce the risk of injury. There is increasing published research that shows core strength training does improve athletic performance and may decrease the likelihood of injury while training and racing. In this article I will present some examples of this scientific research.

First a little background as to what core muscles are. The core muscles are generally considered to be the muscles around the abdomen, back, and pelvis. The muscles of the shoulders and neck are sometimes included in the definition of core muscles. These muscles can be considered stabilizer muscles that are critical in activities because they influence the parts of the body that are not always connected to the core muscles. For example, in an activity such as running, the foot and ankle are immovable during ground contact and stability of the core is required to prevent unnecessary and potentially dangerous ankle and knee movement. For this reason, hip weakness may play a role in knee and ankle overuse injuries in runners (1).

There are six types of movement that the hip can perform. Hip flexion is the movement where the leg is moved directly in front of the body, such as if your are trying to touch something in front of you with your foot. Hip extension is the reverse, such as when you move your leg back directly behind you. Hip abduction is when you move your leg directly to the side from your body. Hip adduction is when you are moving the leg back towards the midline of your body (an example is trying to squeeze a Swiss ball between the legs). Hip internal rotation occurs when you are rotating your leg to point your big toe towards your opposite leg. Hip external rotation occurs when you rotate your leg to point the big toe away from the midline of the body.

While some research has yielded conflicting results in the area of improved athletic performance, a recent article published in The Journal of Strength and Conditioning Research (2) has shown that a program consisting of 4 sessions per week for 6 weeks led to improved 5K run performance in marathon runners. The 5 core exercises the participants performed for each of the core strength training session were designed to target the abdominal, back extensor, and hip extensor muscles. The researchers found that the group that participated in six weeks of core strength training (on top of their regular run training) had a greater decrease in their 5K time compared to a control group that performed their regular run training but did not participate in the 6 weeks of core strength training (average decrease of 47 seconds vs 17 seconds). The authors suggest that the reason their research found increased run performance compared to research not showing improved run performance is the number of core strength training session per week was greater (4 sessions per week) compared to others (2).

In terms of injury prevention, numerous studies have examined the relationship between core strength and the incidence of running injuries (1,3,4,5). Niemuth, et al. (1) recruited two groups of runners (injured and injury free) and examined core muscle strength in the two groups of runners. The six muscle groups tested were hip extensors, hip flexors, hip abductors, hip adductors, hip internal rotators, and hip external rotators. It was found that strength imbalances of the hip abductors, adductors, and hip flexors are associated with lower extremity overuse injuries. Specifically, injured side hip abductors and hip flexors were weaker, compared to un-injured side muscles. The injured side adductors were significantly stronger than the un-injured side muscles. There was a trend for injured side hip external rotators to be weaker, but the difference was not statistically significant.  The authors concluded that adding hip strengthening exercises to strengthen weak hip muscle groups might prevent running injuries or aid injured runners to return to training.

Recently, an article published in the Journal of Athletic Training (3) found that individuals with patellofemoral pain (pain in the front of the knee) have compromised hip strength compared to individuals without pain. The weakness found was in hip abduction and external rotation (3). These results are consistent with previous results showing hip strength abnormalities are associated with patellofemoral pain (4). Weak abductor strength has also been associated with iliotibial band (ITB) friction syndrome (compared to unaffected leg and injury free runners)(6).

So what is the take home message? Weaknesses in the core muscles are associated with lower limb injuries such as patellofemoral pain, ITB friction syndrome, medial tibial stress syndrome, Achilles tendinopathy, plantar fascitiitis, and lower leg stress fracture. Improving core strength and balance may decrease the likelihood of injuries. Finally, improving one’s core strength may lead to improve run performance.

1. Niemuth PE, Johnson RJ, Myers MJ, and Thieman TJ. Hip muscle weakness and overuse injuries in recreational runners. Clin J Sport Med. 15:14-21, 2005

2. Sato K, and Mokha M. Does core strength training influence running kinetics, lower-extremity stability, and 5000-M performance in runners? J Strength Cond Res. 23:133-40.

3. Boling MC, Padua DA, and Alexander Creighton R. Concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain. J Athl Train. 44:7-13, 2009.

4. Robinson RL, and Nee RJ. Analysis of hip strength in females seeking physical therapy treatment for unilateral patellofemoral pain syndrome. J Orthop Sports Phys Ther. 37:232-8, 2007.

5. Zifchock RA, Davis I, Higginson J, McCaw S, and Royer T. Side-to-side differences in overuse running injury susceptibility: a retrospective study. Hum Mov Sci. 27:888-902, 2008.

6. Fredericson M, Cookingham CL, Chaudhari AM, Dowdell BC, Oestreicher N, and Sahrmann SA. Hip abductor weakness in distance runners with iliotibial band syndrome. Clin J Sport Med. 10:169-75, 2000.