Being able to run and feel your pace and level of fatigue is a vital skill to develop with your training. But heart rate training can help further this understand and also help you target very specific physiological adaptations will help you progress as a runner. That means faster running, and longer running without fatigue making you stop, walk or slow down and hit the ‘wall’!  Heart rate training, however, is useless you know the specific heartrate zones to target for you. You need to listen to that amazing organ in your chest when you are running, you need to listen to your heart.

When I say “Listen to your heart,” what I am actually talking about is getting lactate Threshold Testing done to pinpoint at what heartrates your body is using different physiological processes to provide the energy your muscles need to propel you forward through the world around you.  (that doesn’t sound as nice though…)

By discovering and following those heartrate zones, your training can be more targeted, specific and purposeful. This article will describe what LTT is, what the testing is like, and what the results can be used for.

What is Lactate Threshold Testing?

Let’s start by learning how your body creates energy for your working muscles.  When you are working at different intensities, your body uses different processes to create the energy needed to contract your muscles. Your body can work without oxygen to create energy VERY quickly, which is called anaerobic metabolism. It can also work with oxygen, to create more energy but over a VERY LONG period of time, this is called aerobic metabolism.

As I am sure you know, you are breathing while reading this. The body uses both methods to create energy at both times, but the aerobic method (with oxygen), is the primary one used when you are at rest or working lightly.

When you are working at a higher intensity, Anaerobic Metabolism  is used.

why doesn’t the body use anaerobic metabolism all the time? Anaerobic metabolism creates a by-product, lactate. Aerobic metabolism will help transfer and clear this lactate. That is why we need oxygen eventually.

Why does all this matter? Basically, in order to  be able to do more work, and run faster, we need to train both systems. Often times, when someone goes out for a run, they will run at an intensity that doesn’t focus on training one specific system, and because of that, they will not get as much improvement at either system.

We need to train both systems. We can figure out which one is being used at once by seeing how much lactate acid is in your bloodstream at a given exercise (running) intensity (speed). By looking at the rate of accumulation over increasing intensity, we can determine what heartrate you need to train at to improve.

This is done with a 30 minute running test at increasing speeds on a treadmill. We take small blood samples during the test (similar to the amount diabetics take to check blood sugar), and analyse them to see how much lactate is in each sample. From this data we can determine your ‘thresholds,’ and help you better program your running around your heartrates at each threshold.

Disclaimer: this is a simplified explanation of what is happening physiologically as you increase your running intensity. I can go into more detail- but will risk putting you to sleep (as I often do when geeking out over training!).