Why Blood Lactate Threshold Testing?

With all the questions coming in about why you should look at blood lactate testing instead of traditional field testing, I thought I would give a little bit of a 30,000 foot view of why we do it and how the results can significantly revolutionize the gains you are making in your training.

Human Energy Production and Hybrids

Without having to give you a full on lecture about human energy production (ATP-CP, Glycolysis, and the Oxidative System) let’s look at how our body creates energy with a simple comparison to a commonly understood object.  Most everyone understands the concept of the hybrid car, right? The car has both a clean burning battery and a gasoline engine.  Imagine our aerobic system as the battery and our anaerobic system as the gas engine. When the hybrid is driving down the road, cruising slowly, the battery provides the energy.  It has a lot of energy, is clean burning, and super-efficient.  The battery power cannot provide energy quickly though so it can’t go too fast using only the battery. When a hybrid hits a hill or goes down the freeway quickly it needs more energy per minute than the battery can provide – so – the gas engine helps out providing additional energy to the hybrid so it can go uphill.  The problem with the gasoline engine is that it has a small gas tank, it is inefficient, and it creates terrible waste products that can clog up the system.

Our body is the same way. Our aerobic system is super-efficient and can last for a long time. However, it cannot provide a huge amount of energy per minute or per second so we have limited power we can produce per minute.  The gas engine is like the anaerobic system – it can provide energy really quickly but it is inefficient, burns through our limited supply of carbohydrate quickly, and the waste products clog up your legs and can stop them from working.

If in training we can build an athlete to have two batteries we would have an athlete who can produce even more power per minute via the clean burning aerobic system – we will also be saving carbs for the later important sections of a race. We also aim to improve your body’s ability to ‘clean up’ the lactate that is produced when it starts coming on so we can slow the build-up.

Engines vs. Strength

Let’s look at this engine concept with three cyclists – Steve, Sally, and Chris. When we look at the strength of a rider you might think that leg strength is the defining factor on how fast each of them are. You’re wrong.  Let’s take Steve. Steve is 185 lbs and can squat 500 lbs easily. When we complete his test we find that 220 Watts is his threshold.  This means he can ride at that effort for a while but it feels heavy to him. 220 Watts is about 80 lbs of force on the pedals and that is not a whole heck of a lot when you compare that to squatting 500 lbs is it?  Let’s move on to Sally…

Sally is 160 lbs and based on her testing she can ride 220 watts forever as it falls into her easy endurance training zone. She cannot squat 500 lbs like Steve but she can produce that 80 lbs of force on the pedals relatively easy.  Now let’s look at Chris…

Chris is 165 lbs can’t squat to save his life but can ride even MORE watts than Sally can at his easy endurance zone. That 90 lbs of force is NOTHING to Chris.

How does this work – and why does it have anything to do with lactate threshold testing???

It comes down to HOW your body is producing energy. When we look at Steve he can produce 220 watts for a bit, but because he is producing it using more of his anaerobic system, the waste products that are accumulating in his muscle tissue are not buffered or cleared fast enough for him to continue it for longer than about an hour. When we look at Sally or Chris, they both have a more developed aerobic system allowing them to push a greater force while creating this energy using the clean burning aerobic system.

That sounds great but it just sounds like Steve is out of shape and needs to do hill repeats and lots of maximum intervals to increase his strength. This is where most coaches get it WRONG. I was even guilty of it (embarrassingly enough) in my early years of coaching. The problem with using a basic field test and then applying a % to it to create your training zones does not take your body into consideration at all.  It assumes that we are all the same. If you are very underdeveloped aerobically we can see that in the blood lactate test easily. For a small change in heart rate we might see a large jump in lactate accumulation. This tells us – WOAH – we need them to back down on the intensity for a while.  If we just applied a % to the athlete we could actually be doing them a disservice by allowing them to work too hard – incorporating the anaerobic system too quickly.  The reason we want to control the creation of lactic acid in our body in training is that these waste products do nothing beneficial for our mitochondria, the power houses of our cells.

So How Do I Apply My Test Results

Once you have the test done you’ll receive a print out with your personal lactate curve. We will use this data to pin point different markers that will let us set specific ranges that are designed to elicit different responses in your body depending on your goals. Most of the time we find that most athletes need to back way down for 4-5 weeks because they’ve spent so much time blasting their bodies with too much intensity that they have completely wrecked their aerobic system.  With the testing we recommend you get retested approximately 10 weeks later. What we see if you’ve followed our suggestions is that the curve continues to shift to the right showing an increase in power or speed with less lactic acid production at the points previously tested.

If you work with another coach it’s no big deal at all. The ranges are easily understood and the suggestions made in your test make it super easy for your coach to plug them into your training program. It’s a win-win for you and your coach.

My Personal Thoughts and the KEY Takeaway

I cannot believe how my personal training has improved since adopting this method of training and testing.  It’s somewhat embarrassing to admit that I had coached using zones that, while not completely useless, weren’t giving my athletes or me, the true understanding of what each of us needed to work on. If we don’t understand our own physiology how can we manipulate it to our benefit? The key here is understanding the nature of specificity of this testing.  I want my readers to understand why a field test with applied percentage is not ideal.  It is because it assumes we are all the same.  If we are lucky your zones will fall into the right place on how your body functions but that is rare and if you’re not one of the lucky ones you will be training wrong. We take the ranges directly off of your personal lactate curve so you are turning exactly at the points that will give the biggest improvements to your energy supply systems.