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Trail Tips

Trail Stability

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Prevent injury and run better with a strong core

Core strengthening” has become a catch phrase in the fitness and running world. There is no shortage of …

Illustration by Jeremy Collins

Core strengthening” has become a catch phrase in the fitness and running world. There is no shortage of articles and advertisements touting the benefits of an “eight-minute abdominal” workout. And, indeed, for trail running’s variable terrain, having a strong core is crucial to both maintaining proper technique and avoiding injuries.

However, the Holy Grail of many coaches and runners alike, the abdominal “six-pack” focuses on larger muscle groups (such as the rectus abdominus and the external obliques), and is often attained via crunches and sit-ups. But true core training incorporates much more.

Says Joe Friel, author of The Triathlete’s Training Bible and Total Heart Rate Training, as well as owner and founder of Joe Friel’s Ultrafit, an online coaching service, “I make core strength a part of all my runners’ yearly training plans.”

Don’t Buy Into the Hype

Scientific research demonstrates that before the legs even begin to take a stride, the lumbar stabilizers contract to form a corset-like support around the spine, which transmits strength and stability to the lower extremity. If this support system is not working properly, the body sustains impact in a manner that places excessive force on the joint surfaces, creating imbalance and a risk of injury.

Many runners and coaches assume these important smaller stabilizing muscles (the lumbar multifidii, pelvic floor and the transversus abdominus) will be engaged through a pour-over effect from traditional ab exercises. This does not necessarily happen. And research has demonstrated these muscles may shut down in response to pain or trauma, especially if an athlete has a history of injury. Therefore, effective core training targets the deep lumbar stabilizers to protect the spine and other joints.

Says Zika Rea, co-founder of Zap Fitness Foundation and runner-up in the 2005 U.S. National Marathon Championship, “Core training is the single best way to avoid injury. Most running injuries—for example, iliotibial-band syndrome and knee and lumbar pain—whether acute, or overuse, can be avoided by having a strong core, which allows the stress of running to be distributed evenly.”

Get Some Back

While core training is important for stabilizing the lower extremities, it is also crucial to preventing and treating lumbar pain. One study demonstrated that patients with low-back pain had delayed or even absent contraction of the transversus abdominus muscle—a primary lumbar stabilizer. Another study estimated 84 percent of individuals without a history of low-back pain were able to effectively contract the transversus abdominus muscle properly, whereas only 10 percent who had a history of low-back pain were able to perform the same contraction.

This may be due to a change in the way the nervous system performs when challenged by pain or trauma. Portions of the nervous system called ion channels regenerate rapidly, which can cause a rapid decline or improvement in function, depending on the stresses placed on the body (trauma or rehabilitation). It appears pain causes the pathways to the muscles to shut down or become ineffective and, more importantly, the muscles often do not recover on their own.

Back to the Basics

If crunches and sit-ups alone are insufficient core training for trail running, what should you do?

First, if you have a pre-existing injury, see a qualified professional to ensure the problem is a simple musculoskeletal problem and not something more serious.

Healthy individuals should focus on training the small stabilizing muscles of the spine to add strength and rigidity while still allowing fluid movement and flexibility. Abandon the traditional weightlifting approach of heavy weight and low repetitions, because the stabilizers are postural muscles and designed to provide support over an extended period. Since these muscles are composed mainly of slow-twitch fibers, endurance, not gross strength, is the goal. Neurological facilitation—exercising the pathways between the brain and muscles—is a key factor and is different from most basic strengthening programs. Longer contractions are emphasized to improve endurance.

The basic transverses-abdominus (TA) contraction is the foundation of a successful core-training program. The first step involves understanding the “neutral-spine” position. To find this position, start by lying on your back with your knees bent. Then flatten your back so that your spine pushes into the floor to its maximum degree. Next, arch your back the opposite direction as far as possible. Repeat this process several times until you have a good feel for the range of motion in your back. Finally, arch your back again as far as you comfortably can, and then release the tension or movement by about 15 percent. This should leave a gentle inward curve of your lower back and a space between your low back and the floor. This is your neutral spine position; it should feel comfortable. If you feel strain, release the tension slightly more. This position should be maintained throughout the exercise.

Now you are ready to perform the TA isometric exercise, which consists of a gentle contraction of the deep abdominal stabilizing muscle fibers while maintaining a stable back position. Maintain a comfortable breathing pattern without flattening your low back to the floor.

First draw a deep breath, then slowly exhale until it is nearly maximally released. Now, draw your belly button in toward your spine (visualize drawing your abdominal contents inward) while maintaining a neutral spine and steady breathing rate. Hold this contraction for five to 10 seconds. One way to ensure you are doing the exercise correctly is to place your fingers near the front of your pelvis just inside of the bony protuberances. Sink your fingers deeply into your abdominals and feel for a tensing of those muscles.

Once you have the hang of it, practice the TA contraction during various activities and in multiple positions, e.g. sitting, standing and walking.

When you have mastered the TA contraction, utilize it while performing traditional core exercises, such as crunches, sit-ups and squats. A solid foundation ensures that the small stabilizing muscles will be engaged during these exercises. In addition, exercise-ball exercises can be executed more effectively while decreasing the likelihood of injury.

Core Intervals

A great way to incorporate the exercise into your running is by doing core “intervals” on your easy run days. Begin with a 10- to 15-minute warm-up. Stop to perform the TA contraction in a relaxed standing position to ensure correct form. Then, perform three to five 30-second running intervals holding the isometric TA contraction. Maintain a relaxed form. The exercise should provide stability but not rigidity to your form. Repeat this workout weekly.

Thomas Minton, PT, Cert. MDT, C.E.E.S. is a physical therapist and the Fitness and Wellness Coordinator for the Mission Rehab and Sports Clinic in Asheville, North Carolina. You can reach him at