Do you know your lactate threshold?

Happy Monday!

I’m heading out bright and early this morning for a fun new adventure.  BSX Athletics is a local company (remember the app I shared a few weeks ago?) and they have invited our running group to come to the lab for free lactate threshold testing as part of a study they’re conducting to better understand the physiologic adaptations of endurance training.

We were supposed to avoid intense exercise for the last 48 hours, so I moved my long run to Friday and taught spin as usual on Saturday.  I couldn’t resist taking my new Mizuno Sayonara’s out for a  short recovery run yesterday, but I kept it nice and easy.  My legs should be fresh today!


What is my Lactate Threshold?

The lactate threshold is refers to the intensity of exercise at which there is an abrupt increase in blood lactate levels.  Research has shown that the lactate threshold occurs at 80-90% of heart rate reserve (HRR) in trained individuals and at 50-60% HRR in untrained individuals. 

In simple terms, as you run faster, you create more and more lactate.  At a certain point, the body produces lactate faster than the body can remove it and you are forced to slow down.

How is the testing done?

In a lab, tests are performed on a treadmill and blood samples are taken from finger pricks to measure blood lactate concentration, heart rate, power output and VO2 to determine where the lactate threshold is.

Why do LT testing?

Your lactate threshold is approximately your 10k pace, or the pace at which you can sustain a hard racing effort for 40-60 minutes.  However, the only way to have an accurate measure is through Lactate Threshold Testing.

Using your lactate threshold to determine your pace efforts is one of the best ways to improve performance in endurance events.

How to train with your LT?

By training at your LT, you can slowly become more efficient at that pace and push your threshold to a faster pace over time, which will result in better race results.  The “tempo run” is a popular tool to train at your lactate threshold.  Many plans incorporate it weekly.

Greg Mcmillan prefers full spectrum latate training, where you perform tempo runs at your low-end (marathon pace), middle (half marathon pace) and high end (10k pace).  He emphasizes variety for better adaptations.

I’ve never done LT testing before, so I’m excited.  I estimate lactate threshold for the athletes I’m coaching based on their recent race results and use that number for their goal tempo pace and incorporate it in my training as well.

By the way, there are a few ways to do this test on your own (without a lab).  An article in Triathlon Competitor states:

For running, there are a variety of methods you can use to determine your running LT with the help of a GPS device. One method is to run a 10K race and determine your average pace (min/mile) and heart rate for the entire race—this will produce a fairly accurate estimation of running LT. An alternate method is to run hard for 20 to 30 minutes on a moderately flat course and again monitor your heart rate and pace. Pay particular attention to your breathing. When it becomes labored for the first time, you have most likely reached your LT.

The timing is perfect, as I’ll be starting marathon training in just two weeks and can adjust my training schedule and paces accordingly.  My most recent 10k pace was 6:50, so I’m guessing my threshold will be somewhere around a 7 minute mile.  I’ll report back with my results later this week!

Do you know what your LT is? Have you incorporated tempo runs regularly in your training?


45 thoughts on “Do you know your lactate threshold?

  1. I had lactate threshold testing done when I was a student. As part of our exercise physiology lab we got to be the Guinea pigs. Sadly, I wasn’t much of a runner back then but more into mountain biking. It would be interesting to compare the two tests now. 10 + years later and more of a runner. Have fun today!
    Angela @ Happy Fit Mama recently posted..5 Tips For Summer RunningMy Profile

  2. This is so interesting!! I did this once in college as a favor to help out a friend who was doing an experiment however I totally forget what it was!!! I do tempo runs every other week…sprints on the off weeks. I used to not do speed work as much but I really do love it….once it’s over!!
    Fancy Nancy recently posted..Monday MotivationMy Profile

  3. That is SO cool that you’re getting your tested! I’m insanely jealous. I recently wrote a freelance article about another method to estimate your LT. I keep meaning to do the workout — it would be really valuable to know during training.
    Jen recently posted..Breastfeeding and runDisney racesMy Profile

  4. Awesome that you are having this done! It’s always nice to really know your true numbers. I had mine done eons ago and used it for all my training numbers. It’s probably high time I do it again, but I’ll wait until I am done MAF training first. Looking forward to your follow up.
    misszippy recently posted..Feeling a bit like CinderellaMy Profile

  5. I have NO idea what my LT might be. I can’t wait for the follow up to this.

    I do incorporate tempo runs in my training plan. I don’t love them, but it’s nice to know they serve a legitimate purpose, other than torturing me. :)

    PS – LOVE LOVE LOVE your shoes.
    Jenn recently posted..the pressure’s onMy Profile

  6. I never tested for my LT but I have a pretty good idea what mine is (trial and error etc). I’m not a huge fan of tempo runs (I’d rather do intervals or progression runs) but I know they make you stronger so when I am training I try and do a tempo once a week. Do that which you like least, and it will make you stronger.
    Laura recently posted..Good, Bad & Yummy 6/21-6/23My Profile

  7. I had VO2 testing done, and know where my fatigue threshold is from a heart rate perspective. What that pace is depends on the conditions of the day. :)
    I have not had the testing down with blood test as well. Fascinating!
    Mandy recently posted..Another wake-up callMy Profile

  8. How interesting for you! I do not know my lactate threshold. I have only recently begun incorporating speed=work into my training- mostly because my friend is training for a marathon so she feels that all our runner friends need to suffer through speed workouts with her. :)

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  10. i have never had formal testing, but I can definitely feel it when I hit my LT. I didn’t know there was actual testing for this – now I need to do some research before I start training for marathon #2. Man, your blog has been so full of foods for thought lately (well always) – I have a whole notebook of notes i’ve written down for later research!!! Loving it!!!
    Rachel B @ Busy Mama Fitness recently posted..Rock ‘n’ Roll Seattle Marathon RecapMy Profile

  11. How cool! I didn’t realize what a huge dif. there was between trained and untrained people. Wow! I haven’t been doing tempo runs lately but only because I’m doing a 5k almost every week and I feel those are basically tempo runs for me.
    jan recently posted..Mississippi River CreaturesMy Profile

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