The Last Leg of 26.2: What’s Actually Happening?

Let’s envision a hypothetical scenario here. You and a good friend are running the marathon, and both of you have nearly identical athletic and physical qualities. For much of the race, the two of you run in close proximity to one another, and sometimes even side-by-side.

It’s only a matter of time before the finish line comes into view for the both of you. You can see it less than a half mile away, and you begin to feel the rush of accomplishment coursing through your brain–you’re almost there.

Your friend is still running alongside you at this point. But you know what? There’s no place for ties, and a little friendly competition doesn’t hurt. You’ve been running at a steady and manageable pace for much of the race; but now it’s time to bring it. So you begin to run faster. Not a full on sprint–that’s impossible at this point–but maybe an extra stride or two to increase your current mile pace by 10 seconds.

Your friend is right there with you, matching you stride-by-stride. So you continue to run faster, and suddenly it hits you–that incredible burn of fatigue in your legs that permeates your mind and your soul. In your mind, the only thing you can think about is how much this sucks, and how much it hurts. It feels like you’ve hit a wall, and you know slowing down will allow the pain and the burn to dissipate.

But you don’t slow down. Your friend doesn’t either. The finish line is only a quarter-mile away now, and you just have to endure two more minutes of agony. At this point, you’re running as hard as you can, even if it doesn’t look like much to a spectator. The pain doesn’t go away but you’re on autopilot. All you can think about is finishing the race.

And you do. Your friend, who was unable to keep up with you in that very last leg, finishes 10 seconds behind you. You’ve just completed 26.2 miles, and a rush of elation rushes over you as you gasp for air. It’s done.

So, what happened on that last leg of 26.2, and what did it really take to finish the race as well as you did?

On the last leg when fatigue and muscle burn began to set in, you reached what is known as the anaerobic threshold. Simply put, the anaerobic threshold is the percentage of your maximum aerobic capacity (VO2max) at which your muscles begin to burn. More specifically, the term anaerobic threshold refers to a collection of points at which both lactate concentrations in the blood and ventilatory rate increase dramatically. A much more in-depth and scientific discussion of these complexities can be found here: Metabolic Testing Part II: Anaerobic Threshold.

The anaerobic threshold may also correspond with a specific running pace. For example, that increase in pace on the last leg of the marathon took you over that threshold, whereas if you were too stay below it, you could’ve avoided crossing it. Whether or not you would’ve finished the race ahead of your friend is a different story.

The increase in blood lactate concentration is concomitant with an increase in the concentration of H+ (hydrogen) ions. Lactate is actually used for anaerobic metabolism to continue fueling muscles; on the other hand, H+ ions interfere with the contractile ability of muscles.

However, it takes time to metabolize lactate and remove hydrogen ions faster, which is why fatigue and burn set in. Elite athletes have a better ability to metabolize lactate faster, which allows them to quell the rising concentration of hydrogen ions and keep their muscles working and contracting efficiently.

The higher your anaerobic threshold is, the faster your running pace will be before fatigue sets in and you hit a wall. In other words, you are better able to tolerate higher exercise intensities (ie: a faster running pace) because you can work at higher percentages of your VO2 max for longer and without muscle burn.

The key to improving your anaerobic threshold can be best summarized by this simple piece of advice: you have to train above it. We go into more detail about this here in our Move of the Week segment. Watch the video from 4 minutes, 24 seconds onward to cut right to the chase.

In essence, training above your anaerobic threshold means that you are purposely seeking to induce fatigue and muscle burn. However, this stimulus drives your body to adapt to those exercise intensities at which fatigue and burn would normally bring you down, but won’t in the future.

In your training, even if you don’t know what your anaerobic threshold is exactly, you’ll be able to feel it. Your breathing rate will increase and your muscles will burn. Focus on sustaining that feeling for a period of time, before dropping back down to a lower pace. Let the fatigue dissipate, and then go back up to that threshold for repeated bouts. This is the basis of tempo training. An example that would correspond well with marathon training is 10-minute intervals above anaerobic threshold followed by 5-minute rest periods at a slower pace, for 2 sets.

Pushing your anaerobic threshold takes a lot of mental fortitude, but it is best to get comfortable with it in training. Come race day, you’ll know exactly what to expect in that last leg when you decide to surge ahead of the competition.

This is exactly like grinding out the last few reps on the last set of heavy squats or deadlifts. Both of these activities, running and lifting, are physically and mentally taxing. They are also necessary if you want to continue making progress and improving your performance. This should come as no surprise. Get comfortable, with the uncomfortable!

And let’s not forget the mental and psychological benefits of training hard, either. Running can improve both the quantity and quality of neurons in the brain, and the mind-clearing effects of running are well-documented. Training to succeed in the last leg of 26.2 is not only good for your finishing time, but good for you health, too.

by Jeremy Lau

Jeremy Lau is a Senior Staff Coach and Metabolic Lab Manager at Halevy Life.

Jeremy graduated cum laude from Rensselaer Polytechnic Institute with a BSc. in Biomedical Engineering and received his Master’s in Exercise Physiology at Columbia University. In addition to his academic accolades, Jeremy is a Certified Strength & Conditioning Specialist (CSCS).

Prior to joining the team at Halevy Life, Jeremy completed a coaching internship at Cressey Sports Performance, where he coached both amateur and professional athletes, among whom were many professional MLB baseball players.

As an athlete, Jeremy has played baseball competitively for most of his life.