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FR 645: Lactate threshold not detected
Former Member
I have had the watch for a few weeks. The VO2 max is calculated, 48. My max HR is entered, 166. I have the HRM Run chest strap. Ran the test (for a second time (failed both)) and stayed within the prescribed zones as directed...in fact, never strayed from the zones for an instant! After the last 3 minute interval, with my throat sore from heavy breathing and my HR at 164 (close to max), I get the message "Lactate threshold not detected". What the?!?! So, what am I missing? Is there some secret setting I need to change (turn off auto detect, change my watchface?). Any help would be appreciated...thanks. At a minimum I got a good workout (brightside).
Markus, I added 3 bpm to my highest ever record HR of 163. I figured I could maybe get to that level before I dropped from pain... Also, I am 47 so my max using the formula would be 173 (not too far off).
Should it matter though? Given that I was able to run in the prescribed zones for the test without any issues the test should have worked. At no point was my HR too low or too high. The last segment was sufficiently uncomfortable and faster than my 5k pace. I feel like I am missing something in the settings.
The only potential issue is that i wasn't in Zone 1 at all...my warmup was a bit faster than the first segment of the test but I am not sure why that should matter. In any case, it should at least warn me to slow down on the warmup if it would affect the test.
The max HR is at least used to set the zones for the test. Another question: You don't use Beta Blocker medications? Beta blockers may heavily decrease max HR. I assume your max HR is much higher than the ever recorded highest HR. I also assume that you did not reach the heart rate where the watch can detect the threshold (might be higher than 164). I am for example 49, have VO2max of 46/47 and my max HR is 183. My lactate threshold currently is around 162/163, which is about 89% of max HR. Having VO2max of 48 at age of 47 at least says you are in good shape. I think you should change your max HR to at least 173 or higher and then try the test again. I recently did some research for max HR calculations and found this one that seems to be more accurate than the 220 - age calculation: Norwegian University of Science and Technology https://www.ntnu.edu/cerg/hrmax
Markus, thanks for your response...that is an interesting theory...perhaps I am not running hard enough for it to figure the LTHR. Apparently it looks for an increase in HR variability (or something like that) to indicate the LTHR. I am not on any meds. I had the Max set at 175 last time but couldn't sustain a HR in the 162-171 range for that last 3 minute segment so I lowered it for this test. I ran a 5k in 23m15s recently with an average heart rate of 161 and I was spent at the end. Maybe I need to toughen up and deal with the pain. All these years of working at a desk has made me soft!
You do not need to run hard to get a LT detection. Most people can run at LT for at least 20 minutes. So if you are pushing yourself so hard that you can only run for a few minutes, you are already above LT.
Read the instructions I have posted in the thread Markus referred to.
Your HR for 5K is the same as mine. I’m 48 so close to you as well. My max is 172. If you can maintain 161 average for 5K then no way your max is 166. Set it to 172 and try again.
After more than a year with the 645M, I decided to performed the lactate test. first 3 "laps" of 4 minutes were alright. But when it asked for staying 3 min between 160 - 170 then it seems that my HR belt failed. I kept going faster and my HR dropped from 162 to 107 in first 2 minutes. At that point I've reached pace of 3:45 /km . I slow down and HR start going a bit up but not so much. I finished next 3 minutes lap at 138 when I was probably around +172 as I know myself quite well. What failed ? HR belt, lactate test within the Forerunner or my Heart :) ?
