Lactate Threshold Testing - How Often?

LT threshold will change more dramatically if you are in the beginning years of your training.

However, once you reach a certain fitness level, your LT threshold won't change too much and can actually be held stable with little to not LT work.

By way of illustration, My run LTHR was 174bpm 3 weeks before the Chicago marathon 2004.  Post marathon I didn't do any LT work and just did recovery workouts for a few weeks and then slowly worked back up to long slow distance runs.

Several month later my LTHR was tested again it was still 174bpm.  This is an excellent illustration that speed work isn't required to keep your LTHR.  I was a bit miffed at this and got some input from a few coaches, which confirmed this.

Irrespective of this, I almost always get my LTHR checked on the bike AND run prior to any A-priority race that is not a race I can do "full throttle"...so before any 1/2 IM or longer race or any marathon race I get my LT checked again if it's an A-priority race.

For the sprint and olympic distance races, since I've had several years of endurance training, I'm able to simply go all out for these races and not have to pace myself with LTHR.

To address your last question.  My run LTHR is 174bpm but my bike LTHR is 152bpm and the variance between the two fluctuated quite a bit at first...but now I haven't seen a change in either for about 2 years...it's just my pace at these LHTRs that changes.

Unless you know that 7bpm is your variance, I would do a field test or better yet, a blood lactate test for your run LTHR.

Thanks for the thoughful and detailed response!  I love this site.  Anyway, I'll probably do both running and cycling LT tests this season.  Just trying to figure out the best timing.  I have a HIM coming on June 11th (Racing for Recovery) and am very late into my 27 week training plan.  How far before an "A" race did you get tested?

Thanks.

Keeping in mind that a LT test is really a speed workout you'll need adequate time before your A race (of course) but also adequate time BETWEEN both tests.

 The protocol I typically use is 2-3 days between tests (again, depending on how fit your are and used to speed workouts you are) and 2-3 weeks before the A-race for a proper taper.

That's pretty much where I'm at Haley.  I figure I'll try to work it into my last "build" block before the HIM.  Of course I'd also have to remember to actually wear my HRM at a tri before it does me any good.  So far I've only worn it at running races.  And of course I have to watch out for what happened to JeepFleeb in the unique tanning department.