Lactic threshold confusion

Discussion in 'Cycling Training' started by beison, Feb 12, 2009.

  1. beison

    beison New Member

    Joined:
    Feb 18, 2008
    Messages:
    52
    Likes Received:
    0
    So I wanna start by saying I think I'm pretty clear with what the concept of a lactic threshold is. I've done the research and everything there makes sense. I suppose I could be missing something, though, and maybe that'd explain my confusion below...

    My problem is trying to identify my own lactic threshold. I know there are multiple types of tests, but since i'm in college and kinda broke, I opted to do a self test on my trainer. I did the 10 min warmup, 20 min max effort test, and took my hr average of the 20 minute effort. From what I understand, that 20 min average is a pretty close estimate of what my LT is.

    I did this test at the beginning of the start of my preseason training, to guage where I was. In a ride a couple days later, I also got my max hr measured on the same trainer with the same hr monitor. The results were as follows...

    Max HR: 207 bpm
    20 minute max effort average: 198 bpm
    so...
    my Lactic Threshold is about 198bpm, or about 95-96% of my max HR.

    Again, from what I understand, this is a really high number, like even most of the protour riders don't have LT's like that. But I don't believe the number is correct.

    Whenever I try to do LT interval training,

    eg. 4-6 minutes at my threshold, 2 min rest

    It's extremely hard to get my HR up to even 190 for more than 3 of these intervals. By the third interval, my legs have that telltale burn that says I've gone anerobic, meaning I've been working past my threshold. If 198 were my real lactic threshold, I should theoretically be able to go at this intensity indefinately, but I can't even manage more than three or 4 intervals at that intensity. That's why I think 198 isn't my actual lactic threshold.

    So I guess my question would be, what do you guys think of what I just described, have you ever heard of it before, and is there some other way for me to find my actual lactic threshold (aside from going in to get an all out finger prick test in a sports medicine lab), so I can have a workable number to train with?

    PS I know a power meter would really help here, but again -- broke college student, so I kinda gotta work with what I've got.
     
    Tags:


  2. Piotr

    Piotr New Member

    Joined:
    Jan 29, 2007
    Messages:
    794
    Likes Received:
    0
    Firstly, I would not say that your maximal 20 min effort average HR is your HR at LT. That is because your maximal 20 min effort is probably considerably more intense than a typical LT pace, depending on how you define that pace. Even a 1 hr time trial effort (referred to as FTP on this forum) is somewhat harder than what is usually understood as Lactate Threshold in exercise physiology. A 20 min maximal effort has an anaerobic component to it and from my experience can be as much as 108% of FTP. This is why your average HR over 20 min was so high.

    Secondly, heart rate has a considerable lag in response to an effort, so don't count on it ever reaching your projected LT HR after only 6 min. If I were to take a swag at it based on your post, I'd say that your 1 hr maximal pace HR is 185-190. In a 1 hr TT you probably shouldn't expect to reach 185 for about 10 min, assuming that my guess is correct and that you pace the effort properly.

    Thirdly, I will venture another guess that your 4-6 min LT intervals are way harder than LT, because you're trying to reach what you believe to be the correct HR. This is the typical argument against training by HR. Either a person tries too hard because their HR seems too low, or they're not trying hard enough when rested and fresh, because the HR seems too high.

    If you don't have a power meter, I think some good old fashioned "perceived exertion" may be in order. IOW, use the force Beison! :)
     
  3. DJA

    DJA New Member

    Joined:
    Dec 15, 2005
    Messages:
    101
    Likes Received:
    0
    beison, I take it from your post you have only done the test once? Try repeating the test a couple of times and see if you can repeat those figures.

    I've always thought that LTHR is what you average over a 40k TT and at a 20min TT the avg HR would be more like 105% of LTHR which would make your LTHR 188 which is still 90% of max and an excellent number. This might explain why you are struggling in you intervals.

    PS isn't "just started pre-season" a bit early to be doing LT workout the season is long don't burn your self out to early.

    Total agree with PIOTR. HRM are best used in efforts over 20min and power reading are best for effort under 12mins. 20 to 12min use a combination of both. The "force" is an under used skill these days. :cool:
     
  4. beison

    beison New Member

    Joined:
    Feb 18, 2008
    Messages:
    52
    Likes Received:
    0
    I think I'm getting what yer saying, I guess, as crazy as it sounds, I'm not really use to the perceived effort scale... either I'm training with a HR monitor, or, I'm racing in a pack, and trying not to pay attention to how much I'm hurting :D.

    If I were to train with some perceived effort intervals, how hard should I feel like I'm going for a good LT increasing workout?
     
  5. beison

    beison New Member

    Joined:
    Feb 18, 2008
    Messages:
    52
    Likes Received:
    0
    Actually while this is the first time I did it this season, last season I did the same 20 min avg 3 or 4 times, and managed about 195 HR. I figure coming in this season in a little better form than I was in last season, these numbers would make sense, at least in a continuity sense.

    As far as this being a bit early for intervals, actually I'm waaay behind schedule and should have been doing these 3ish weeks ago or more-- the collegiate season starts super early and our first race is in about 2 weeks!
     
  6. Piotr

    Piotr New Member

    Joined:
    Jan 29, 2007
    Messages:
    794
    Likes Received:
    0
    I could not possibly add to anything already written here about PE:

    http://home.trainingpeaks.com/articles/cycling/power-training-levels.aspx
     
  7. DJA

    DJA New Member

    Joined:
    Dec 15, 2005
    Messages:
    101
    Likes Received:
    0
    As far as this being a bit early for intervals, actually I'm waaay behind schedule and should have been doing these 3ish weeks ago or more-- the collegiate season starts super early and our first race is in about 2 weeks![/QUOTE]
    Sorry missunderstood where you are in your training plan. After re-reading your first post I relise my error.:eek:

    Have you tried do the intervals at slightly lower effort level? You may find if you back them off a little you will get through them. Then start lifting the level back up gradually over the coming weeks.;)
     
  8. stevechow

    stevechow New Member

    Joined:
    Mar 11, 2006
    Messages:
    86
    Likes Received:
    1
    It's extremely hard to get my HR up to even 190 for more than 3 of these intervals. By the third interval, my legs have that telltale burn that says I've gone anerobic, meaning I've been working past my threshold. If 198 were my real lactic threshold, I should theoretically be able to go at this intensity indefinately, but I can't even manage more than three or 4 intervals at that intensity. That's why I think 198 isn't my actual lactic threshold.

    It's easy. You minus 10percent. Do it again see how much can you take. If it works, add back 5percent. Once you know the base, then maybe can take the measurement using HRM every 2 weeks to check your performance.


    Cao,
    The crazy cyclist.
     
  9. bartjoosen

    bartjoosen New Member

    Joined:
    Sep 25, 2003
    Messages:
    28
    Likes Received:
    0
    You can complete 20min on 198 avg, but not 3x5min on 190?
    Maybe you are pushing to hard the first min of your interval to reach your HR. Try to back it off the first interval, and feel how hard the interval should feel on the end of the interval.
    Then you can use this PE for your next intervals.

    Also, if you like a homebrew test for the determination of your LT, you could try a Conconi test on your stationary trainer.

    HTH

    Bart
     
  10. Alex Simmons

    Alex Simmons Member

    Joined:
    Mar 12, 2006
    Messages:
    2,471
    Likes Received:
    20
    I would not at all be surprised if due to HR response lag that averages for short efforts were not above threshold HR levels. See below:

    [​IMG]
     
  11. daveryanwyoming

    daveryanwyoming Well-Known Member

    Joined:
    Oct 3, 2006
    Messages:
    3,857
    Likes Received:
    97
    Exactly! Nice graph Alex.

    All Steve's demonstrating is why HR isn't very useful for pacing short intervals. It takes approximately 7 minutes for my HR to reach the mean during a 20 minute isopower L4 interval and it continues to slowly drift higher all the way till the end of the effort. During a 5 minute L5 effort it often doesn't get as high, at least not until the third or fourth interval.

    If you don't have a PM then just pace your 3 to 5 minute L5 intervals in such a way that you can just barely complete them without backing off the pace. Sure it will take a couple of efforts or maybe a couple of sessions to find that pace and it will change with fitness. But the bottom line is you want to sustain 90% or more of your best possible effort for the duration without starting too hard and fading or having extra juice to punch it at the end. The PM makes the process of finding that pace a bit quicker but in the end you can figure it out with nothing more than a stopwatch. HR is often misleading for short efforts or even the start of longer efforts.

    -Dave
     
  12. JBlighty

    JBlighty New Member

    Joined:
    Jun 6, 2009
    Messages:
    2
    Likes Received:
    0
    Firstly the problem with all of this topic is that its an inexact science so results will vary from person to person by a small amounts (<5%) however lets get out terms right, it is no longer Lactic Threshold but Lactate Inflection Point (LIP) and this occurs at 85% MRH, this is because 85% MRH is when the body will start to work anaerobicly as apposed to aerobicly. because at 85% MHR the body can not get enough oxygen to the muscles to remove the lactic acid already being produced and contract the muscles so the body switches to the Lactic acid system to produce energy and because more lactic acid is being produced as a bi-product and not being turned into pyruvic acid it starts to build up thus LIP. With the numbers that people so far have been talking about (95%) this is infact where your Adenosine Triphosphate- Creatine Phospahte (ATP-PC) system kicks in and is the reason you can't perform multiple intervals at the same intensity. Just some extra facts as well the burning feeling when performing exercise is infact excess Hydrogen Ions and an in balance of Sodium and Potassium Ions in the muscles. In summary your LIP should be around 176 BPM.

    James
     
  13. Ultraman

    Ultraman New Member

    Joined:
    Jul 25, 2005
    Messages:
    1
    Likes Received:
    0
    How can you state that everyones LIP occurs at 85% MHR? This will change depending on how well trained an individual is. In matter of fact your 85% MHR is probably at best a mean avg for highly trained individuals but it simply is not the same for every individual period. Individuals who are not trained at all might have an LIP as low as 70% MRH where as a highly trained individual might possibly have an LIP as high a 90% MHR.
     
  14. JBlighty

    JBlighty New Member

    Joined:
    Jun 6, 2009
    Messages:
    2
    Likes Received:
    0
    The difference is that untrained indaviduals will have a lower hart rate thus the 85% of their MRH will be a lower number, so if someone has a low hart rate their LIP will still be at 85% but the BMP will be lower than the trained athlete. Also because a trained athlete is able to consume more oxygen there LIP will still kick in at 85% however the lactic acid will build up slower and you can work at the same intensity for longer as you have a tollerance to Lactic acid and this is why different people (trained athletes) will work anaerobicly for longer than others (untrained athletes)
     
  15. frost

    frost New Member

    Joined:
    Oct 25, 2007
    Messages:
    414
    Likes Received:
    3

    This I would indeed call a lactic threshold Confusion...
     
  16. nfeht

    nfeht New Member

    Joined:
    May 3, 2009
    Messages:
    46
    Likes Received:
    1
    I can hold my just under anaerobic threashold 178bpm for an extended period of time easily. I determined mine through a VO2max and metabolic rate test recently. the only way i can think of determining ones LT would be to get tested or see what max heart rate you can hold for an extended period of time.
    my local gym offers a VO2 test if one of yours does i would have it done to determine your threasholds. It has increased the effectivness of my training greatly.
     
  17. bartjoosen

    bartjoosen New Member

    Joined:
    Sep 25, 2003
    Messages:
    28
    Likes Received:
    0
    you local gym? If I understand correctly this is based on some power output you made on a stationary trainer, and corrections for bodyweight were made?
    No mask to measure your oxygen / CO2 whatever?

    This is just an estimation of your VO2 max, and if you can sustain for a long period, I think its an under estimate.

    Best regards

    Bart
     
  18. nfeht

    nfeht New Member

    Joined:
    May 3, 2009
    Messages:
    46
    Likes Received:
    1
    no its not an estimate i was on a stationary trainer and had a mask to measure the O_2 and CO_2 correlation for body weight were also made. all the equipment used to test an olimpic athlete's VO2 was used. this gym is associated with the local hospital, hence why they have access to all the nessicary equipment. prior estimations of my VO2 were 75-80 (godly high). the actual test resulted in a VO2 of 55.9 (much lower)
     
  19. bartjoosen

    bartjoosen New Member

    Joined:
    Sep 25, 2003
    Messages:
    28
    Likes Received:
    0
    Sorry, made my conclusions too fast :rolleyes:
    Forget what I wrote ;-)

    Bart
     
  20. nfeht

    nfeht New Member

    Joined:
    May 3, 2009
    Messages:
    46
    Likes Received:
    1
    dont worry about it. no harm done
     
Loading...
Loading...