# Anaerobic and lactate threshold difference



## woodys737 (Dec 31, 2005)

Coaches. Regarding anaerobic threshold vs. lactate threshold:

I'm reading they are generally considered one and the same, but wouldn't AT come before LT (meaning AT is the reason you eventually reach LT)? If the same, okay. If not, are they so close that setting heart rate zones doesn't really matter?

Thanks for a great forum!


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## Sub (Feb 13, 2004)

They are two names for the same thing. Heart Rate Zones are important in order to train and optimize different physiological systems. Hope this helps and thanks for the question, we need to get this forum going!


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## reikisport (Aug 16, 2006)

Yes and No
While they are close they occur at 2 different points.
If you ask 10 different coaches/sport science people you'll get about 8-10 different answers.
The deffination that is used most for LT(1) is:a 1 mmol/L increase in blood lactate over exercise baseline. 
Anarobic Threshold (AnT) is the point that Lactic acid starts to accumulate and is attributed to the failurs of the CV system to supply O2 to muscle tissue.There is also a dispropotionate rise in ventilation. 
So yes there is a difference and Lt(1) happens "earlier" AnT would happen much "later".
LT2 would be a better marker(IMO)to use to base your training zones. but whatever way you chose to base your Training Zones use that same protocol each time otherwise the results are not very good.
Great to see a seperate coach page here.
CoachT


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## Sub (Feb 13, 2004)

I agree if you want to get specific. Coaches are going to disagree on this and most if not all coaches/training is based off of one particular number though that may not be 100% acurate.


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## woodys737 (Dec 31, 2005)

reikisport said:


> Yes and No
> While they are close they occur at 2 different points.
> If you ask 10 different coaches/sport science people you'll get about 8-10 different answers.
> The deffination that is used most for LT(1) is:a 1 mmol/L increase in blood lactate over exercise baseline.
> ...


Just slightly confused. If AnT is the point where lactic acid start to build up, how can LT(1) happen first. I am getting on in age and new to training, so even if they are roughly 5-10bpm apart, that's huge to me as far as setting zones is concerned. Did I misinterpret your post?


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## reikisport (Aug 16, 2006)

Because LT (1) is just a 1mmol/l rise. The athlete is still predominatly using aerobic metatolism(higher % of FATS). By the time you reach AnT the athlete is using predominatly anaerobic metabolism(Higher% CHO). Once the athlete reaches this point they normaly cannot continue much longer(8-10min or so).
The reason I was being a little more specific is too many athletes(coachs too) use these terms interchangabily {AT (aerobic Threshold), LT(1 &2) AnT(Anaerobic threshold), OBLA(Onset Blood lactate)VT (Ventilatory Threshold] to mean the same thing and they aren't. Yes they are close(kissing cousins) but still different. I think as coachs/sport science/ExPHYS people we should at least be consistant with the terms we use in our day to day work. So at least we know what we are comparing and talking about.


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## zhmontana (Aug 16, 2004)

so what was the difference between Lt1 and Lt2?


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## zhmontana (Aug 16, 2004)

*LT vs FTP vs VO2Max intervals*

Ugh... starting a new thread instead of stealing this one...


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## Sub (Feb 13, 2004)

zhmontana said:


> so what was the difference between Lt1 and Lt2?


Lt1 occurs at a lower level of blood lactate (about 2mM blood lactate) and Lt2 occures at a little higher level (at about 4mM).

You can only sustain exercise above the Lt2 level for a brief period of time, from a few minutes up to maybe an hour or so depending on how far above that level you are. Exercise between L1 and L2 can be potentially be sustained for 1-2 hours also depending on where within that range you exercise.

This is all a very technical look at threshold and like I said most coaches will pick a method of obtaining an LT and work from that with consistency.


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## asgelle (Apr 21, 2003)

reikisport said:


> If you ask 10 different coaches/sport science people you'll get about 8-10 different answers.
> The deffination that is used most for LT(1) is:a 1 mmol/L increase in blood lactate over exercise baseline.
> Anarobic Threshold (AnT) is the point that Lactic acid starts to accumulate and is attributed to the failurs of the CV system to supply O2 to muscle tissue.There is also a dispropotionate rise in ventilation.


At last fall's USCF Cycling Summit, there was a presentation that showed a couple dozen or so definitions of LT and as I recall, while some were more popular than others, the feeling was there was no general consensus that any one was more useful than the others as long as a consistent definition is used. Which leads to the question of how fine this concept of threshold can be sliced. As I understand it, LT is measured by choosing a point on the lactate concentration - intensity curve to represent the limits of the aerobic metabolism system to keep up with energy demands. The choice of the exact point on the curve leads to the myriad definitions, but the concept is the same and is indicative of a single metabolic system. Therefore, does it really make sense to divide this one breakdown into many subsets? Further, if one subscribes to the Monod critical power paradigm (which has been shown to model performance quite well within it's limitation to periods neither too long nor too short), there are only two parameters governing performance: the aerobic contribution entering as critical power, and the anaerobic part from anaerobic work capacity. From this, aerobic metabolism is again described by a single parameter, so I would like to understand how the discussion here breaking aerobic metabolism into at least two components fits in with Monod.


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## Sub (Feb 13, 2004)

asgelle said:


> At last fall's USCF Cycling Summit, there was a presentation that showed a couple dozen or so definitions of LT and as I recall, while some were more popular than others, the feeling was there was no general consensus that any one was more useful than the others as long as a consistent definition is used. Which leads to the question of how fine this concept of threshold can be sliced. As I understand it, LT is measured by choosing a point on the lactate concentration - intensity curve to represent the limits of the aerobic metabolism system to keep up with energy demands. The choice of the exact point on the curve leads to the myriad definitions, but the concept is the same and is indicative of a single metabolic system. Therefore, does it really make sense to divide this one breakdown into many subsets? Further, if one subscribes to the Monod critical power paradigm (which has been shown to model performance quite well within it's limitation to periods neither too long nor too short), there are only two parameters governing performance: the aerobic contribution entering as critical power, and the anaerobic part from anaerobic work capacity. From this, aerobic metabolism is again described by a single parameter, so I would like to understand how the discussion here breaking aerobic metabolism into at least two components fits in with Monod.


I agree, and that is how most people train. That is also why I kept my first response simple, there is no reason to break it down to this point. I think it was a case of one-upmanship.


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## bill (Feb 5, 2004)

Isn't it true that no one really knows what causes fatigue and muscle failure, but we know that the lactate produced by the body is used as fuel and that the presence of lactate prolongs muscle function and contributes to endurance? Do I have that right? And doesn't the very use of the term "lactate threshold" perpetuate the myth that lactic acid causes fatigue pain and muscle failure?


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## Sub (Feb 13, 2004)

bill said:


> Isn't it true that no one really knows what causes fatigue and muscle failure, but we know that the lactate produced by the body is used as fuel and that the presence of lactate prolongs muscle function and contributes to endurance? Do I have that right? And doesn't the very use of the term "lactate threshold" perpetuate the myth that lactic acid causes fatigue pain and muscle failure?


It's not the lactic acid specificly that causes the muscle failure, but a byproduct of the lactic acid system (H+) that eventually causes the fatigue. The build up of H+ due to lack of oxygen to remove it from the system is what makes the muscle acidic and will eventually impair function.


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