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Dynamic Core Stability: The 100-Up, Reloaded

Enhance dynamic core stability for running with the 100-Up drill.

By on April 8, 2014 | Comments

Stay the CourseMy approach to treating running injuries has steadily evolved over the past few years. Fresh out of school, I was focused on pathology: what hurts and how do we heal that tissue as quickly as possible.

My exposure to the Institute of Physical Art has made my approach vastly more comprehensive, encompassing mechanical, neuromuscular, and motor control factors: not simply in the injured areas, but throughout the system, recognizing the interconnectivity of the entire system. For example, a chronic foot and ankle pain issue might have vital dysfunctional components in the arm swing, or even the neck.

More recently, I’ve come to realize the importance of internal, physiological factors in injury and healing, and how metabolism–intensity-dependent energy systems–affect tissue stress and healing.

But I keep learning. Mostly because people–including me–continue to get injured!

Getting to the Core

A major component of run mechanics–and in comprehensive running-injury treatment–is the core-stability system. Core stability, in its simplest definition, is proximal stability and distal mobility: moving the arms and legs on a stable, strong trunk and pelvic base.

When the base is not stable, bad things can happen to the moving parts. As one co-worker puts it, “A weak core is like trying to fire a cannon from a canoe.” Another puts it as, “a rope pulling on a marshmallow wall.” Without a stable base, the things–muscles, tendons, ligaments–pushing or pulling on the base are overstressed.

But besides keeping us together, the core-stability system is a speed and power generator: not only does the core generate power through facilitating that arm and leg motion, but it also saves energy by storing it, not allowing aberrant motions, like bends and twists and collapses, to rob you of that stored energy.

The importance of core and gluteal muscle strength is widely known: all runners know about it, and all of us do some core strengthening at some point. Yet the bulk of what we do, even what we dole out as healthcare professionals, is largely either slow or static movements, or faster movements that are nonspecific to actual running.

Frequently, core and glut muscles are facilitated and strong, yet when a runner strides out, the same issues–inefficient trunk and pelvic motions–persist! Drills and cues can help, but fatigue tends to wipe away their effectiveness. My challenge as a clinician and a runner is to develop core stability with direct carryover to running.

It was time to get specific.

Dynamic Stabilization, In Stride

Three years ago, I came across an interesting video promoted by The New York Times and Born to Run author, Chris McDougall. In the video, he identifies a running drill he discovered in studying runners from the turn of the 20th Century, called ‘The 100-Up.’

He demonstrates this exercise, which was developed by a runner named W.G. George in England in the late 1870s. The drill, quite simply, is marching or lightly hopping in place. The value, so I thought, came from the pattern–reciprocal leg and arm action–and the endurance strength obtained from doing a hundred reps!

I never integrated this exercise into my practice or run routine, because I felt my exercises and run specific mobility drills were superior.

Until recently.

Dynamic Running Stability, In-Pattern

Beginning this winter, perhaps timed with the onset of rain and snow in Oregon, I began to see a slew of injured runners with one thing in common: the inability to keep their trunk stacked on top of their pelvis and hips. While their aches and pain are varied (hip pain, lateral thigh, knee, ankle or foot–the sky’s the limit), they all had difficulty keeping themselves stable on a single leg.

This is a problem, because putting all your weight on one leg (and balancing it there for a third of a second) is what running is! Searching for a way to practice this single-leg stability, I recalled the George exercise, and McDougall’s video.

I began to use it. And people began to get better more quickly and sustainably.

The benefits of this exercise are two-fold:

  1. The 100-up, when done specifically, is ‘in-pattern’ with efficient running mechanics: it replicates the arm, leg, scapular and pelvic patterns seen in core-driven running gait mechanics. As such, performing this exercise reinforces this efficient pattern.
  2. The exercise–namely the second, jumping progression–represents the specific demands of running: the ability to push off one leg and land on the other, in-pattern. But most importantly, you must stay balanced!

What I found with folks performing this exercise is that they would have the most trouble on the side of their pain. Folks with back, hip, thigh, knee, shin, or foot pain on the left would have more difficulty ‘sticking the landing’ on that left side without wobbling or flat-out falling to that side. In effect, their lack of core stability on that side caused increased stress to their problem area.

The exercise then became the gatekeeper between healthy runners and those still needing work. Those who could do it, could return to running (yet still practice it, and on increasingly challenging surfaces). For those who could not, it was back to the drawing board (or treatment table) to address any dysfunctions before trying again.

The Exercise

Begin standing on one leg. To emphasize the core-driven running pattern, use your abdominals to shorten the trunk on the drive-knee side, and the pelvis will hike, slightly, without slumping the back. The opposite, stance-side trunk will lengthen, helping to facilitate gluteal activation. Arm swing follows suit, with elbow down and back with hip up, and elbow up and forward on the stance side:

Dynamic Core Stability - 100-Up - flat

The standing version of this exercise simply involves reciprocation: marching in place, alternating legs and arms. Any runner who has difficultly (outside coordination) with this exercise likely needs additional core facilitation (or joint mobility).

The jumping version is more exciting:

The very best at this exercise demonstrate what I call, ‘strong, soft, and stable:’ they have a strong jump and push off, land softly absorbing the force through the core and glut muscles, and remain stable upon landing.

The microcorrections noted in my video will actually help develop more strength through the trunk, pelvis, and hips.

Exercise Progressions and Utility for Ultrarunners

Once mastered, the 100-Up can be progressed to more challenging surfaces, including:

A soft mat or pad:

Dynamic Core Stability - 100-Up - pad

… and even a BOSU ball!

Dynamic Core Stability - 100-Up - ball

This drill is important for all runners, but even more so for ultrarunners, because this quick reversal–especially on uneven surfaces–replicates the demands of technical terrain, particularly on downhills. The ability to run quickly and efficiently down steep, technical hills requires the instantaneous dynamic stability found in the 100-Up. When this drill is well mastered, the trunk and hip stabilizers will absorb the bulk of the downhill stress, not the joints and muscles of the legs.

So give it a try, whether you’re injured or simply looking to improve your trail running ability!

Joe Uhan

Joe Uhan is a physical therapist, coach, and ultrarunner in Auburn, California. He is a Minnesota native and has been a competitive runner for over 20 years. He has a Master’s Degree in Kinesiology, a Doctorate in Physical Therapy, and is a USATF Level II Certified Coach. Joe ran his first ultra at Autumn Leaves 50 Mile in October 2010, was 4th place at the 2015 USATF 100k Trail Championships (and 3rd in 2012), second at the 2014 Waldo 100k, and finished M9 at the 2012 Western States 100. Joe owns and operates Uhan Performance Physiotherapy in Eugene, Oregon, and offers online coaching and running analysis at