Lessons From Exercising Until Hitting the Wall: A Reflection

ABC News' Dan Childs reflects on what it felt like to "hit the wall."

— -- I was certain my eyes were going to pop clean out of their sockets. Logically, I knew it couldn’t happen. But in that moment, I was sure they were going to shoot right out of my skull and bounce across the floor like two ping pong balls.

What did I learn from hitting the wall? Beyond the nausea, tunnel vision, burning lungs, and jelly legs -- it just plain sucks.

To help the ABC News Medical Unit further explore this phenomenon, NYU Langone’s Sports Performance Center generously allowed us to take full advantage of its facility. It also offered the services of two of their exercise physiologists, Harry Pino and Heather Milton -- our tour guides along the path to physical exhaustion.

So, what were the major lessons learned?

Lesson One: There is more than one “wall” … and the one I hit was certainly not the worst. As Pino and Milton explained, what I encountered is known as the lactic acid wall. Lactic acid is a pesky byproduct of the body’s normal functions, and your muscles ramp up production during exercise. This lactic acid is the reason for the “burn” you feel when you are pumping iron or squeezing out that final quarter mile on the exercise bike. Once your muscles start producing lactic acid faster than your body can get rid of it, the acidity builds up in your muscles until you are forced to stop exercising. That was the point on the treadmill when my legs threw in the towel.

Lesson Two: There’s much more to fitness than just being fit. Here’s the thing: I’m not an athlete. It’s something that has been pretty clear to me from a young age, reinforced during countless humiliations during pickup football games and a lackluster childhood career in YMCA baseball. So, when I received my extensive analysis from NYU Langone, I was both surprised and humbled.

The surprise? My VO2 max, a measure of my body’s capacity to use oxygen to fuel exercise, was 50.7 mL/kg/min -- a level that Pino described as “not bad for an old guy.” I’ll take it. And apparently, my anaerobic capacity -- in other words, my body’s ability to generate bursts of power for a short period of time -- isn’t too shabby.

But beyond that, things dropped off pretty precipitously. Endurance is a problem. My running mechanics are strange and problematic, characterized by imbalances and inefficiencies that I never noticed before. For example, I tend to put my leading foot too far forward, my knees aren’t flexed nearly enough, and I bounce down the pavement as if on a pogo stick. All of this puts more stress on my feet, legs, hips and spine. The sobering conclusion: “This increased impact may lead to injuries such as: tibial stress fractures, patellofemoral pain, and hip pain.” Yikes.

Additionally, Milton’s evaluation of my movement revealed that I am at risk of exercise-related injury. One particularly notable issue: “Decreased gluteus medius strength and delayed gluteus maximus activation.” Translated: I literally need to get my ass in gear.

Something I’ll keep in mind the next time I lace up my shoes for a run.