Mikki Volk and Angel Miranda rowing during a WOD at Shadow CrossFit

As a coach and gym owner, one of the most common things you’ll hear is people saying they haven’t seen a change in their weight. It truly is. It’s almost as if this change is the only thing that actually matters to most people. That everything else that is accomplished no longer seems to matter and goes unseen, but hey, that’s why I’m here. To talk about the changes you can’t see, and why they’re just as important as the ones you can.

The Lactic Acid Threshold

Let’s start with something that sounds complex, but is actually much easier to understand than you might think; lactic acid. I’m sure most of you have heard about lactic acid at some point or another throughout your life, as it is the common chemical compound our body produces that we attribute to that burning sensation in our muscles that results in soreness and fatigue. So let’s start by hammering out the basic science first, because well, science can be pretty cool;

During intense exercise, glucose (the human bodies key energy source found in carbohydrates, grapes, and dextrose to name a few) gets metabolized into pyruvate (energy supplying acid).
This rapid glucose breakdown results in lactic acid during physical activity. It’s produced more rapidly than our bodies are able to remove it, resulting in fatigue.
Though other chemicals are involved, this is a small part of a process known as the Citric Acid Cycle (also know as the Krebs Cycle or Tricaboxylic Acid Cycle).

That’s a very rapid, and blunt, description of what lactic acid is. In latent terms, it’s what makes us feel tired during aerobic or anaerobic activity. Have you ever noticed if you carry say, groceries, for a long distance that your shoulders and arms begin to burn? That is lactic acid in full effect.

Now, if we look back at that nice bold topic listing about the lactic acid threshold we are getting into change that often goes unnoticed. A threshold is the level, rate, or amount at which something comes into full effect. Each person has a different threshold at which lactic acid begins to become unbearable. This threshold however can change over time.

Increasing the Threshold (give it your all, for a longer period of time)

The answer here is simple; the more often you work, the more work you can do over time. Lets take pull-ups for example, since it’s a goal most people work towards and use bands (assistance) to get there. So here’s the scenario;

    John starts coming to CrossFit XYZ, and can’t do a pull-up yet. The coach gives John a combination of bands (say a green + red), and suddenly John is able to do five strict pull-ups!
    A few weeks go by, and John is getting frustrated that he hasn’t improved from the green + red band combo. The coach then asks him to perform a set of max reps, and John gets ten without a struggle.
    The coach then takes the red band away, leaving the green, and John does five again.

Lets break this down a bit, as a few things just happened. To start, something was accomplished on day one that John didn’t think he could do via band assistance, five strict pull-ups. After those few weeks go by, we notice he’s able to now do ten with his old bands, and five with less resistance! Very exciting. You see, not only did his strength increase as noted by doing five pull-ups with less bands, but our lactic threshold has increased as he’s able to now do ten at his old resistance instead of five.

Let’s look at one more quick example by picking on running a little bit, as it’s the worlds most common form of fitness. Maybe we’re training for a 5k race, and before that race I am going to run multiple 5k’s to condition my body to perform well. On my first attempt, and only a mile in, my legs and lower back begin to burn as lactic acid builds up. Fast forward a month, and multiple 5k runs later, my body no longer hurts after a mile but instead hurts after two miles. We’ve successfully increased our threshold, providing us the ability to go harder for a longer period of time.

The Unnoticed Result

The interesting thing about this chemical change, is that it often goes completely unnoticed by most people that aren’t aware to look for it. We work, and work, and work without noticing our increased capacity to perform without actually becoming fatigued. Next time you’re in the gym, performing an activity you’ve performed before but you don’t think you’ve “improved,” ask yourself if you can complete one more rep than you did before. If you could only do five pull-ups, but now you can do ten, then you’ve improved more than you’re willing to give yourself credit for. The same goes for how much further you can now run without becoming fatigued than you could before.

Sometimes, the simplest of improvements can go a long way.