I am asked yet again how to find one's lactate threshold heart rate (LTHR) by doing a 30-minute time trial. I really don't understand what seems to be so difficult about this. All that's required is running (or riding) as hard as you can possibly go for 30 minutes ALL BY YOURSELF. It must be solo. Doing this as a part of a race or with training partners will change the outcome. Your number will be too high. If you want to do it with others or as a part of a race then you need to make it 60 minutes duration instead of 30.
Once you've captured the data in your device download it to your software and find your average heart rate for the last 20 minutes. That's an approximation of your LTHR (also often referred to as anaerobic threshold or functional threshold heart rate). If you don't have software all you have to do is push the lap button 10 minutes into the test. That will then capture the last 20 minutes as a standalone "interval." Your average heart rate for that portion is close to your LTHR. Note that this DOES NOT mean that you go easy for 10 minutes and then turn it on with 20 minutes remaining. It's 30 minutes all out.
Do not watch your heart rate during the test. You're not trying to produce a given number. Do not be concerned with anything other than are you going as hard as you can go right now. If the answer is "yes" then you are doing the test right.
I don't understand why this seems to confuse people so much.
There... I feel better now. :)
Martin C--You're joking, right?
Posted by: Joe Friel | 04/30/2011 at 06:12 AM
Hi Joe
Thanks for the grumpy ;-) explanation. The confusion I have is that I was going as hard as possible and I blew 18min into the test. Full-on come to a standstill, throw up, faint, blue in the face implosion! Could not even muster up a minute cool-down (luckily it was on the indoor trainer). I was going TOO hard. So I still think, SOME pacing is required other than "as hard as you can possibly manage at that exact moment"?
Posted by: Lona (Cape Town) | 05/01/2011 at 02:24 AM
Lona--It should be fairly obvious that if you are doing a 30-minute TT that you have to pace yourself. It's just like you were doing a 20k TT. No different. As hard as you can go means taking into consideration that you still have x minutes to go. It exactly like racing a given distance. No different.
Posted by: Joe Friel | 05/01/2011 at 06:06 AM
Thanks for the review and I'm glad I came to visit your site because I learned a lot about this subject. Keep going! :)
Posted by: seattle chiropractor | 05/01/2011 at 06:11 AM
Hello Joe.
I want to ask you why you recommend for testing on an indoor trainer (in the cold winter) the graded exercise protocoll (with an increase of for example 20 Watt every 1 or 2 minutes till exhaustion - i think its not easy to find LTHR) instead of the 30minutes TT. What is the reason why you don't want to do the 30min-TT on an Indoor Trainer or whats better with the Step-Test? Chris
Posted by: Chris | 11/27/2011 at 11:11 PM
Hi Chris--You can do either. Most people find 30 min all out indoors to be a real challenge. But some can do it ok.
Posted by: Joe Friel | 11/28/2011 at 12:40 PM
I did the LTHR - 172BPM and my FTP was 252w for the last 20mins. The first 10 mins of the test I had values of LTHR - 171 and the FTP was 279w. Was that a successful test even though my power was 27w lower in the 20min section of the test?
Posted by: Jolon Sabo | 01/09/2012 at 12:14 AM
Jolon Sabo - For power you use the average for the entire 30 minutes. Only for HR do you drop the first 10min.
Posted by: Joe Friel | 01/09/2012 at 09:22 AM
I did the time trial outdoors alone. Average HR for first 10min was 192bpm and 199bpm for the last 20min. Is this okay? I've measured my HR across several other monitors, and it does run high.
Posted by: Amateur | 02/08/2012 at 02:11 PM
amateur--If that's what you got, that's what it is.
Posted by: Joe Friel | 02/09/2012 at 07:07 AM
Thanks, most people kept telling me it's too high. I'm currently reading your book only at chapter 4.
Posted by: Amateur | 02/09/2012 at 07:40 PM
I just did the 30m TT running test. I'm quite confident I followed your directions properly. I'm curious in that my average HR during last 20m was 185 which is 3 bpm lower than my max 188. I'm 37yo and I've never been able to get my HR over 188 no matter how fast or long I sprint. Does it make physiologic sense that my lactate threshold HR is so close to Max HR? Does this mean anything? Or am I obsessing too much over data? Thanks for your help. Charlie
Posted by: Charles Luther | 03/24/2012 at 11:40 AM
Hello Joe. I recently got your book "The Cyclist's Training Bible". Based on that I did an LTHR field test today. I went as hard as I could for 30 minutes on my bicycle and took the average heart rate of the last 20 minutes as the LTHR. This was done afer a 15 minute of easy warm up. But that average Heart rate came out to be 199. My maximum heart rate on the Bicycle is about 204 as seen a couple of weeks ago when I was racing uphills with my friends. Even when racing with friends my heart rate stayed between 194-199.
Now from what I am reading around an LTHR of 199 with the max heart rate of 204 seems too high (Although I have seen my max heart rate go to 214 when I am running). This 30 minute trial was an all out effort. I felt like I could have thrown up towards the end. All through the time trial I had an eye on my heart rate monitor and it stayed between 196 and 202.
So does this seem really abnormal to you?
I am 27 years old and have been into sports since I was 12 years old. Mostly running.
Posted by: Saurabh Sharma | 10/20/2012 at 10:58 PM
Hello.. and best regards from Mexico city...
following your book my LTHR is 188, but my HRmax is 183... It is safe to train with this LTHR?
Posted by: Emilio | 11/03/2012 at 08:31 PM
Emilio--that's not possible. Are you using a formula to come up with max heart rate? If so, don't. In fact, don't even worry about it. Of no use.
Posted by: Joe Friel | 11/05/2012 at 06:00 PM
Hi Joe - first, I just wanted to say "thank" for your Training Bible. I've used it to coach myself successfully to the pro level. Structured training has really paid off for me!
I had to do my LT test indoors, due to weather. My LT heart rate was a couple beats lower than in the past. Might this just be because I am doing the test indoors?
Does the LT heart rate get higher as one gets fitter, or does it stay pretty constant?
Posted by: Sarah Jansen | 02/12/2013 at 08:21 AM
Sarah J--HR varies a few beats from day to day just because we are humans. But LTHR will stay about the same once your fitness has reached a moderate level. Whether or not it really changes with age is an entirely different matter. I'm afraid motivation is a part of what explains the drop in MHR with aging. Mine has been the same since 1983 when I got my first HRM.
Posted by: Joe Friel | 02/15/2013 at 01:01 PM
Hi Joe,
Thanks so much for all your contributions to endurance training literature and knowledge.
I just did your bike test and the average heart rate was 176 -- 20 to 25 bpms higher than my "guesstimate" lactate threshold heart rate from 8 months ago, which I calculated from an estimated max heart rate and a "beginner" RPE test. (Eight months ago was when I got back into triathlon after a multiyear hiatus from any exercise.)
I'm not surprised such guesstimates are so far from the test result, and I'll use the new test result as my new training/zone benchmark.
A question: Would high temps/humidity skew the test in any way? I live in Central America, and typically lunch hour is the best time for me to train. That's when I did the test. It's usually mid-80s to low-90s with a good bit of humidity and very strong sun.
Thanks and regards, Ross
Posted by: Ross | 05/16/2013 at 12:07 PM
Ross--HR will stay the same. Power (or pace) at any given aerobic HR will typically be lower/slower.
Posted by: Joe Friel | 05/17/2013 at 01:55 AM
Hi Joe,
Thanks for your reply! That makes sense. I don't much enjoy training in the heat, but given that I'll be racing in similar conditions, it's probably good for me.
Posted by: Ross | 05/17/2013 at 01:55 PM