by Shawn McDonald
If you’re running a five km race, you can get away without strengthening your core, because you’re finished before your form can fall apart. When you’re running an ultramarathon distance though, it helps to have a strong core to carry you along mile after mile after mile.
Maintaining a fluid stride, good posture and efficient mechanics for many hours takes the combined effort of prime moving muscles (calves, quads) along with stabilizer muscles running from the hips to the trunk. Running form often degrades after a few hours due to fatigue of both prime movers and stabilizers, possibly resulting in injury or decreased performance.
Core training provides many benefits for a small time investment. Running power and efficiency can be improved and form can be better maintained for a longer time.
Role of the core
Your core muscles function to support the hips and spine in correct alignment from front to back, side to side, and up and down. Trunk muscle groups include hips abductors, adductors, and flexors; gluteals, various abdominals, the psoas, pectoralis, and lower and upper back muscles. The core groups have key roles in a fluid running stride. They stabilize the center of your body, allowing for efficient generation of force by the legs, arms, and torso. They also provide balance so you can maintain your center of gravity (located just behind and below your belly button) when running on uneven or hilly terrain. With strong core muscles, your spine is kept in a neutral position (s-shaped), lowering pressure on discs in the back and even helping to relieve back pain if you have had that problem in the past. A stronger core lowers the risk of injury since the pounding stresses of running are better spread to the limbs and joints when good skeletal posture is maintained and muscle imbalances are minimized. A strong core will also allow you to better regain your balance and avoid a fall when you trip while running. A well-developed core also forms a platform from which your arms and legs work as you run, leading to more efficient form. Form failures often result due to a combination of fatigued legs and tired back, shoulder, and hip muscles. A strong trunk can help you ‘power’ up hills by combining strong legs with a vigorous, controlled arm swing. Combining weight training, core strengthening, and agility/balance work along with stretching to improve flexibility can help you lengthen your stride, allowing you to cover more ground at your current stride frequency.
Developing core strength
A core training workout can be performed every 2-3 days (depending on your current training phase), in a session lasting 20-30 minutes. The core work can be combined with a short, easy run or short bout of aerobic cross-training, either of which should be performed before the core exercises to act as a warm-up. Then you should stretch your back, trunk, and limbs for about ten minutes prior to the start of the core work. Be sure to perform the core exercises with proper form, in a controlled manner and cadence. Finish the core workout with about ten minutes of additional stretching as a cool down. The abdominal crunch, prone plank and side plank form the core of a trunk workout, and are a great place to start.
Lie face up on a floor mat with your knees bent, feet flat on the floor, and arms crossed over your chest. Initiate a single rep by lifting your head, shoulders, and upper back off the floor while pushing your lower back into the floor. Inhale and hold your breath as you start the lift, curling your upper trunk as much as you can. Hold the full tilted position for a second, and then exhale and slowly return to the start position. Complete two sets of 20 crunches with 30 seconds of rest between each set.
Lie face down on a mat, then lift your trunk and legs off the mat while supporting your weight on your elbows/forearms and toes (see pictures in the article on pfitzinger.com). Hold the plank position while keeping your head (looking down at the mat) in line with your spine, for 10-60 seconds. Then rest for an equal amount of time, completing 5-10 holds per set. Make sure your shoulders, hips, knees, and ankles are in a straight line, not too low, which puts a lot of stress on your lower back.
Lie on your side on a mat, then lift your trunk off the mat, using your elbow/forearm and the side of your foot for support. Don’t sag, maintain a straight line from ankle to shoulder. Hold for 10 - 30 seconds, then lower, rest and repeat, 5 – 10 holds per set.