The Importance of Lactate Threshold Testing

If you’ve been around the sport of triathlon long enough, you’ve probably heard something similar to this:  “Sorry dude, I can’t go with you up Lookout Mountain, I’m only supposed to be in Zone 2 today.”, or “Man, those 4x 4-min intervals at Zone 5 were a killer!!”  If you’re a beginner though, you probably think that there is a secret language that you don’t know yet.  What these athletes are talking about are training intensity zones, and the most common method that coaches use to define these zones is the Lactate Threshold test.

The lactate threshold test is performed in a variety of ways, with the most common being a step-test (i.e. increasing pace or resistance on a specific timed interval).  It’s done on either on a treadmill or on the bike with a trainer while taking periodic blood samples that measure absolute value of lactic acid in the blood (measured in mmol/mL for all you Chemistry geeks!).  The Lactate Threshold Heart Rate is defined then, as the place where either the value of lactic acid crosses 4 mmol/mL or there is a significant jump in value of greater than 1.5 mmol/mL.  (There is some subjectivity as to where the specific LTHR is and can even be different for different types of athletes.  But what is more important is that the testing protocol observed during baseline testing is maintained on subsequent assessments – only then is the LT test valuable).  Once the coach is armed with the LTHR, pacing/power zones can be created based on that value.  The zones typically differ for different sports – for the run, I use the following adapted from Joel Friel:  Zone 2 is 85-90% LTHR; Zone 3 is 90-95%; Zone 4 is 95-100%; and Zone 5 is greater than 100%.  For the bike, I use Andrew Coggan Zone Calculation:  Zone 2 is 68-83% LTHR; Zone 3 is 84-94% LTHR; Zone 4 is 95-105%; and finally Zone 5 is greater than 105%.  Again, this is subjective by each individual coach, but the importance is consistency.

The lactate threshold test also gives coaches quite a bit more information than just the LTHR.  It becomes the baseline by which to measure improvement throughout the course of training.  For example, if an athlete runs a pace of 7:00min/mi at a lactate value of 4 mmol/mL and when we test her again in 6-months, she runs that same pace with a lactate value of 3.5 mmol/mL, then we have made a significant improvement.

Below you will find the results of an LT test that I performed on an athlete earlier this year on the bike:

LT Test

As you can see in the graph above, the lactate threshold curve crosses the 4 mmol/mL value at approximately 190W with a corresponding Heart Rate of approximately 153 beats per minute (There is also a significant deflection of 1.4 mmol/mL at that same point).  We defined this as his LTHR.  His zones, then are as follows:

Zone 1:  Less than 104bpm

Zone 2:  105 – 128

Zone 3:  129 – 143

Zone 4:  144 – 161

Zone 5: Greater than 161

This test was done in September on an athlete who is currently looking to improve his major limiter which was the bike.  Over the last two months, he has been strongly focusing on the bike and when we test again at the end of December, we hope to see this entire curve shift to the right.

The importance of a Lactate Threshold test cannot be understated.  In addition to a baseline measurement, having these training Zones can gives coaches and athletes insight into how your body is physically adapting to training stresses.  Correlating these numbers with Rate of Perceived Exertion (RPE) can give coaches and athletes leading information into whether the athlete is getting ill or worse, approaching the precipitous cliff of overtraining.

I strongly encourage all of my athletes to get a lactate threshold test done.  In fact, starting this Friday and running through the end of December, for any new athlete, I am offering a Free LT test ($150 value) with a 3-month coaching commitment, or a Free LT Test ($150 value) and the first month free ($200 value) to any with a 6-month minimum coaching commitment.

Happy Training!!!

Justin Chester

Head Coach, TriCoach Colorado

  • Triathlon and the Sport of Competitive Eating

    What possibly could this article be about?  There are probably no two other groups who differ more than triathletes and those who compete in competitive eating, yes that’s right, competitively eating hot dogs, tacos, pizza, etc.  But I assure you that there is at least one person in the sport of competitive eating whom we all can learn a lesson from.  I recently listened to a Freakonomics podcast where Steven Dubner interviewed Takeru Kobayashi.

    In 2001, the world record for the number of hot dogs eaten in 12-minutes during the annual Nathan’s Coney Island Hot Dog Eating Contest held each July 4th was 25 1/8 hot dogs.  Takeru Kobayashi came in that day and broke that world record, not by one, or two, or even five…. he ate a whopping total of 50 hot dogs!!!  Yes, he practically doubled the world record that day.  If you’ve never seen Kobayashi, you may have an image in your mind as to what he looks like, but I assure you that you are wrong – he has a slight build and weighs about 130lbs.  So how did he fit 50 hot dogs into his stomach?

    He simply approached the problem differently.  Instead of looking at and dwelling upon the current record or even looking at how many hot dogs he’d need to eat to simply win the contest, he approached the problem by asking himself how many hot dogs are possible and developed a strategy on how to eat a single hot dog faster.  Kobayashi says, “Human beings tend to make a limit in their mind of what their potential is.”  This limit, he goes on to say, is an artificial barrier that we put upon ourselves by either something we’ve heard or other social norms.  But if we throw away those thoughts and simply redefine the problem, then our own human potential is typically far greater than what we think.

    Often times in casual conversation with folks, it comes up that I’m a triathlete and triathlon coach.  Quite often I hear “Oh, I could never do one of those?”  When I reply that “Anyone can do a triathlon,” the excuses start to come out…”My knees hurt” or “I can’t swim” or “I don’t have the time to train” or “I’m too old”.  The question is:  Are these artificial barriers?  Where did these thoughts come from?  Are these the social norms within your circles of friends?

    I even hear barriers given by triathletes who look to go faster, or win their age group, or do an Ironman, etc.  “I’ve done a sprint but I could never do an Ironman.”  “I could never win my age group.”  And to be honest, I’ve heard myself say some of these things.

    Kobayashi developed a new strategy where he would dunk the hot dog in the glass of water which made it easier to down.  Other competitor would drink water as they consumed the hot dogs to help force the food down, but Kobayashi found that the process took up limited stomach space and wasted valuable time.  The “dunking” method used less water, was faster and achieved the same results.  He demolished the barrier by analyzing what was possible.

    When sitting down with athletes to help create goals, I force them to dream beyond those barriers because it is the mind that is the greatest limiter.  As Henry Ford once said, “Whether you think you can or you think you can’t, you’re probably right.”

    So what are your barriers?

  • Navigating Your Garmin

    Many of the athletes that I coach often ask me ask me whether they should have a GPS device for measuring time/distance/HR for their workouts.  My answer is typically a resounding yes!  It provides invaluable data both in real-time and information for post-workout analysis.  But the next question from my athletes usually comes after they bought their shiny new Garmin:  “How do I set this thing up so I can use it?”

    The question is typically not how to use the device – I think many of these manufacturers make devices fairly intuitive even for those who are technologically challenged.  Rather the question is “what do I look at?”  The Garmin 910 has 39 different possible data fields when it’s in swim mode; 53 when in run mode; and a whopping 70 when in cycling mode.  All of this data cannot possibly be useful while in the middle of your long ride on Sunday.  So what is important on your ride, or your run, or even your swim?  Is it different in racing versus training?  It all boils down to a simple question:  What’s Important Now?  You and your coach can do the post-workout/race analysis, but what’s important now?  Let’s break it down:

    First things first though.  I set my watch to have 3-data field on the primary menu for each sport and 4-data fields on the second menu for each sport.  But I primarily look at the menu with 4-data fields (I leave the 3-data field with the default information).  I know there can be more data fields on a particular menu, but during a workout or a race can you effectively process more than 4 pieces of data at any given time?  And remember that increasing the number of data fields will lower the font size of each field making it more difficult to read.

    NOTE:  Below I am going to describe specific data fields for the Garmin.  If you have a different device like a Polar and Timex, many of these data fields exist but with a different name.


    In the pool, you likely have a prescribed set of intervals that you are doing during the swim like 4×100 or 8×50.  Answering the question of what’s important now, I find that information about the specific interval that I just finished is valuable information for me.  For example, if I’m doing a set of 8×50 with a rest interval of 20-seconds, after I finish one of the 50s, I hit the wall and then the lap button on my watch.  I want to know how fast I did that  50, I want to know how many strokes I took or more specifically my strokes per length, and I want to know stroke rate (especially if it is a limiter for me).  But then I also want to know the time for the current interval because that is what is going to tell me my current rest interval and once that time hits 20-seconds, I hit the lap button again and take off for my second 50.  For longer sets like 400’s and 500’s, if you have trouble counting laps then you may possibly replace stroke rate with Interval Distance

    So specifically for the Garmin, here are the 4 data fields that I use in the pool:  Time – Last Interval; Time – Interval; Strokes/Len. – Last Int; Stroke Rate – Last Int.  Other useful fields on a separate data page may include:  Distance – Interval, Pace – Last Interval, Time (for total elapsed time)

    During a race however, your device is simply going to be a tool that records data for post-race analysis since it is not practical to stop and look at your watch.  But you may simply want elapsed time on the main screen so once you exit the swim, you can get an idea of how fast your swim was.

    Side note:  I find it humorous that there is a data field that tells you the stroke you’re performing.  If you have to look at your Garmin to determine which swim stroke you’re performing, you quickly need to find a coach.


    For the bike, the first question we have to answer is:  What additional devices do you have on your bike?  Do you have a power meter?  Do you have a cadence sensor?  (Of course you have a HR monitor, right??)  As a coach, I find it extremely important to have a cadence sensor and while I also find it important to have a power meter, I understand the cost-prohibitive nature of power meters (but the price is coming down!).  So I’m going to assume that you have a cadence sensor and give you the 4 data fields that are important, but I’ll also give you some power based fields that are also important.

    For the bike, what’s important is information related to the intervals that you’re currently doing because it is real time feedback and you can adjust.  The fields that I like to see are Cadence; HR Zone (assuming you have a current LT test); Current Interval elapsed time; and Current Interval distance.  With a power meter, I replace Current Interval distance with either 10-second power or power zone if you have a current FTP test.  On your Garmin, here are the specific fields:  Heart Rate Zone; Time – Lap; Cadence; Distance – Lap.  If you have a power meter, replace lap distance with either Power Zone or Power – 10s Average.

    These don’t necessarily change for race day.  If you’re not using power, then you’ll like want to set up your watch to auto-lap on a specific distance like 10-mi or at some even division of the race course like 14-mi. for long-course and Ironman.  Other useful fields for the bike include Speed if there are sections on the course where there’s a speed limit, and Time – Elapsed.


    The run is very similar to the bike in “what’s important now.”  During training, you’ll want information about the specific interval that you are running.  Imagine your workout looks like this for the main set:  4×4-min @ HR ZN 4 with 4-min walking recovery.  At the very least, you’ll want to see Interval Time and the HR Zone to make sure that you get the correct effort level in.  You’ll also want the Interval distance because in this particular workout, you should see roughly the same distance for each of the interval (if the interval distance changes significantly, then you need additional aerobic conditioning).  If we change the workout slightly to be distance based (i.e. 4 x 0.25mi.) then you’ll use this field as the indicator as to when to hit the lap button.  Finally, I like to have current pace on my watch as well although that can easily be switched out with Pace – Average if that is workout goal.  For the Garmin specifically, the fields are as follows:  Heart Rate Zone; Time – Lap; Pace; Distance – Lap.

    If you have the Garmin foot pod, then data related to cadence (Cadence, Cadence – Average, or Cadence – Lap) is likely important.  Data like ground contact time is not as useful in real time – save it for post workout analysis.

    During race time, these fields do not change significantly however, I do typically set up auto-lap at 1-mile so I can see my splits.  If you have a specific pace you are aiming for then changing Pace to Pace – Average may be a better option.

    Coach J