Difference between anaerobic and aerobic threshold

aerobic threshold is the fastest pace you can run with out accumulating significant lactic acid in the blood

1 hr pace vs ~2.5 hr/marathon pace

I believe this is how it is:

Aerobic threshold is within the window of effort before you start to accumulate lactic acid in the bloodstream.

So, in the aerobic zone you are building your endurance and don't really get tired, think base period or recovery runs. You should be able to run easily in this manner for 1 to 4 hours without getting wiped out because the muscles are clearing out waste product very efficiently and your heart rate isn't all crazy and you're not burning a great amount of calories. This would equate to an 8-12 hour race pace if you raced in your aerobic zone.

Anaerobic threshold is right above the tipping point, leaving the aerobic window.

So, in the anaerobic zone your muscles are getting fatigued by waste product, your heart is thumping and you're burning more calories.

Once you get past this threshold there are more complications to the training paces - steady state, tempo, cruise intervals, intervals, speed specific work and sprint work. Each one up the ladder is harder to recover from and is shorter in duration.

ANarerobic vs aerobic wrote:

What is the Difference between anaerobic threshold and aerobic threshold

They are the same (in a trained runner so close % wise to the max heart rate). Call it the lactate threshold and you dont need both terms.

Joe Friel pegs the Aerobic threshold to be about 20 bpm slower than anaerobic threshold.

however, I think the term aerobic threshold is a bit silly.

Then the "anaerobic threshold" is neither...

ccrunner609 wrote:

They are the same (in a trained runner so close % wise to the max heart rate). Call it the lactate threshold and you dont need both terms.

This is completely wrong.

Canova speaks of training to get the AeT as close to the AnT as possible, but even then it's a few percentage points difference.

Bang wrote:

You should be able to run easily in this manner for 1 to 4 hours without getting wiped out because the muscles are clearing out waste product very efficiently and your heart rate isn't all crazy and you're not burning a great amount of calories. This would equate to an 8-12 hour race pace if you raced in your aerobic zone.

This isn't accurate either. You should NOT be able to run easily at your AeT for multiple hours at a time.

That is a RACE effort (as mentioned marathon pace for faster runners) and is NOT sustainable for 8-12 hours.

Nonsense.

I can see that, running for hours on end at anaerobic threshold isn't doable but, I broke my words into two paragraphs and the 8-12 hour race pace paragraph is referring to the aerobic zone in general, not the threshold. 10 hours in aerobic would be almost no soreness and 2+ hours at AeT would would feel like death if you were world class.

Bang wrote:

I can see that, running for hours on end at anaerobic threshold isn't doable but, I broke my words into two paragraphs and the 8-12 hour race pace paragraph is referring to the aerobic zone in general, not the threshold. 10 hours in aerobic would be almost no soreness and 2+ hours at AeT would would feel like death if you were world class.

Still not making a lot of sense.

AnT (lactate/anaerobic threshold) is approximately the pace you could sustain for ONE hour. AeT (aerobic threshold) is approximately 2.5 hours.

Now what you're proposing regarding 9-12 horus isn't even in the same ballpark regarding 8-12 hours. That has nothing to do with anything regarding AeT or AnT, which is what the thread is about.

Also, asserting there'd be no soreness after running 8-12 hours is absolutely laughable.

These terms aren't always well defined. For one, a threshold implies some kind of boundary, while these energy transitions are more like some kind of continuum. Your anaerobic systems are in use in your sleep, and your aerobic systems maximize in a two-mile race.

Some simple physiological definitions:

- Anaerobic threshold, often called lactate threshold, is the point where lactate accumulates more than it is used up.

- I've never seen a good definition for aerobic threshold. We are aerobic above and below it. Assuming it must be a threshold for something, I always think of it as the threshold between fat burning and sugar burning.

I'm sure these definitions are wrong, but, unless you are a physiology student, you don't need to dwell too much on these scientific definitions.

For training purposes, we only need to come up with some simple approximations of the desired intensities.

Here are some common estimates of aerobic threshold:

- marathon pace

- MaxHR - 45 beats

- 2 mmol

Here are some common estimates of anaerobic threshold:

- 1 hour race pace

- MaxHR - 25 beats

- 4 mmol

Add to estimates: aerobic threshold = 85% of 5k pace, anaerobic threshold = 92% of 5k pace

rekrunner wrote:

I've never seen a good definition for aerobic threshold. We are aerobic above and below it. Assuming it must be a threshold for something, I always think of it as the threshold between fat burning and sugar burning.

Not got my copy to hand but I am pretty sure Canova, in his marathon book, defines it as the pace that accomplishes the maximum amount of fat burning. Go slower and you preserve more carbs but you also burn less fat; go faster and you burn less fat and more carbs due to the higher demands.

It equates to marathon pace for most good runners, though Canova talks about the sub 2:06 guys as running marathons at higher intensity now.

Hadd used to talk about the importance of training and raising AeT - he emphasised always running below it to raise it (going above it would teach you to burn the wrong fuel) and used HR to monitor that. The key session was 4-5km reps - if your HR was rising on a third rep then you were above AeT. He reckoned that you should be able to get AeT up to a whopping 88%MaxHR with focussed training.

Here are the thresholds I could think of:

A) - that point where you transition from Sprint to Endurance

B) - vV02 max - self explanatory here

C) - the point where you are starting to feel the race using up your anaerobic fibres for aerobic use

D) - that point where you are no longer able to be running strong without the aid of food.

I`ll name these few:

A) - Anaerobic Threshold

B) - vV02 max Threshold

C) - Lactate Threshold

D) - Aerobic Threshold (this explains why nearly ALL marathoners crash late despite being evenly paced)

For a decent runner, here is the range you can think of:

A) definately under 800m

B) 3k-4k pace depending on how fast you are

C) 10 Mile - Half Marathon pace

D) 20 Mile - Marathon pace (or just faster)

"Anaerobic threshold is neither." -Coggan

Don't worry about the precise definitions. They've evolved anyway.

Some people define aerobic threshold as the point when reliance on glycogen as a fuel outpaces reliance on fat as a fuel - i.e., glycogen becomes the primary substrate. Other people have different definitions of this same term.

Anaerobic threshold has several points of definition. The one that can be most precisely measured is synonymous with ventilatory threshold, when ventilation of CO2 begins to increase at faster rate than total ventilation. Lactate threshold is a hazier concept since there often isn't a precise inflection point of lactate accumulation.

To find a desirable "threshold" in practice, just learn how to get in that zone where conscious effort isn't a factor and actually seems to go down as you fly along in a good rhythm and at a good pace. Make sure you approach this zone from the slow side each time, since relaxation is essential to spending the optimum amount of time there.

Here is a detailed link which explores in depth the ambiguity and absurdity of the question, not to mention the physiology:

http://www.lactate.com/threshold.html

Interestingly, after a long discussion, about 3/4ths the way through, they ask and answer:

"Are these thresholds important?"

"... While knowing the lactate threshold is important for competition, knowing the threshold exactly may have less relevance for training despite our long discussion above."

My sentiments exactly. Making physiological based training zones is a proven, effective way to categorize different intensities, that can then be balanced against the individuals strengths and weaknesses. But getting the thresholds (or even the physiology) exactly right is less important than incorporating personal feedback into the training.

rekrunner wrote:

Making physiological based training zones is a proven, effective way to categorize different intensities, that can then be balanced against the individuals strengths and weaknesses.

I may be reading something wrong into your statement. So just consider this a general rant. However, I'd say that making physiological based training zones has proven almost worthless for effective training. The bulk of ex phys guys the last 50 years have mostly advocated endless VO2-max intervals. We all know that doesn't work well over time.

Another example is when a practical ex phys guy like Jack Daniels advocates running easy runs at almost 80% heart rate because physiologically that should correspond to something special. For most people that doesn't work at all.

Frankly I've never heard of any successful training method that was first proposed by physiologists.

Regarding the current topic, I'm starting to think that the notion of so called thresholds has done a lot more harm than good. We can talk about 1h pace and we can talk about lactate values, but there is no "threshold" that tie these two together.

Anaerobic threshold = ~3/4 effort

Aerobic threshold = ~1/2 effort

According to Hadley, there is about 4.5% difference in pace between anaerobic and aerobic threshold. He says that this will vary some based on natural predisposition (such items as muscle fiber make-up and bone structure) and that the range is from 3.5% to 5.5% (cover 99% of runners) with 4.5% being the most common (i.e norm).

If Anaerobic threshold = 5:00 per mile

using the 4.5% rule

than aerobic threshold would = 5:14 per mile

This seems to mesh well with what Vigil said at a recent conference, where he gave ranges 12-15 seconds for elite runners and 15-20 seconds for good high school/college runners.

I suppose it depends on how you specifically define each. Some use blood lactate levels (i.e. 2 mml vs 4 mml) but I think Hadley said he uses a time based definition of:

Anaeobic threshold (which he calles Lactate Threshold) is equal the maximum pace you can hold for 1:00-1:15 in an all out effort. (Obviously this gives you a small 3-5s range).

While Aerobic threshold he defines as the maximum pace you can hold for 2:00-2:30 in an all out effort.