This month’s Triathlete has an article by Matt Fitzgerald that points out that lactate doesn’t cause muscular fatigue. My question then is, of what use really is lactate threshold? That line is so ingrained in our training practices it’s hard to redefine it. Our inability to sustain activity above this line seems now to be due to a series of factors (brain regulation, other waste products, depolarization) so perhaps we should simply start referring to it as the ‘Sustainability Threshold’. Especially considering the brain’s role as a regulator, it seems now that a lot of athletes may be backing off too early when they see their LTHR when, in fact, their brain and other factors would allow them to go a few beats harder. Add to this the whole matter of the accuracy of LT calculations all based on 4 mml when the rate of lactate removal seemingly varies from person to person so, 4 mml may be pre LT for some and post for others. I am no expert so please correct me on any inaccuracies in the above.
I ask the exercise physiologists out there: Is the lactate threshold dead, and, what do we now call that line?
This is what I took from it although I have thought this for quite some time. I’m pretty sure I read it in the Lore of Running.
At what people call LT, Lactate does accumulate but it’s because we aren’t able to use it as fuel and it’s not a byproduct from the fuel the muscles are using.
So the training methods work but for a different reasons than they thought.
I like to read Matt Fitzgerald’s articles. I have a great deal of respect for him.
How about if you said that lactate threshold pace or power is closely associated with the pace you can hold for an hour. Would that help?
The idea is the same, go above lactate threshold pace and you’ll be slowing down pretty quickly, how quickly determined by how far over the line you go.
The reason may be different, whether it is acidification, or central drive, or angels dancing on pins, LT as a marker still has its uses.
However, I think the term “functional threshold power” or pace captures the idea of a threshold without trying to explain the physiological causes whether they are related to glycogen use, lactate accumulation, or anything else.
Bingo: Functional Threshold - thanks, Kevin. I should have thought of that. I Googled it and came up with a great article by Hunter Allen. He writes: “…we’ll let the exercise physiologists debate the definition, but for our purposes in developing the correct training plan for you, we will define ‘threshold’ as the average wattage that you can sustain over a 20 minute test. This is often referred to as your ‘functional threshold’.”
I would feel it safe to say you can apply this to running as well by substituting pace or some other workload for wattage.
I’m still interested to hear a more scientific opinion on this topic as well.
The reason may be different, whether it is acidification, or central drive, or angels dancing on pins, LT as a marker still has its uses.
I have not read the article, but I like the way you put it above. LT - or whatever you want to call it is still an important marker. However, like most things people seem to get all worked up about numbers. They despartly want to see LT expressed in some number or on a graph or in a specific heart rate.
I think what Matt may be getting at is that their is a mental component to this on the regulatory side of things - perhaps a pain or discomfort threshold or a subconcious ability to find that edge of their LT and just surf along it. Good endurance athletes know how to do this. They can find that edge and hold it right there for an hour. And if they are maxed out at the end of this effort, that’s a pretty good estimate of their LT.
If that LT number, whatever it is, goes up with training, then they can cover more distance in that hour - they are fitter and in theory they should be faster at all levels of intensity across the spectrum of effort.
On the bike it seems to be an hour…on the run, I’d equate that same effort to 10K race pace I can hold my 10K effort/intensity for longer on the bike than I can for running.
How about if you said that lactate threshold pace or power is closely associated with the pace you can hold for an hour.
I’ve been harassed before for saying the same thing. I believe you are talking about Maximum Lactate Steady State (MLSS). Lactate Threshold is acctually significantly slower. I often refer to it as LT training pace rather than LT pace because training at FTP or MLSS is targeting improvement in your LT, but its not atcually LT pace.
At what people call LT, Lactate does accumulate but it’s because we aren’t able to use it as fuel and it’s not a byproduct from the fuel the muscles are using.
I’ve read the exact opposite on both of these points.
Bingo: Functional Threshold - thanks, Kevin. I should have thought of that. I Googled it and came up with a great article by Hunter Allen. He writes: “…we’ll let the exercise physiologists debate the definition, but for our purposes in developing the correct training plan for you, we will define ‘threshold’ as the average wattage that you can sustain over a 20 minute test. This is often referred to as your ‘functional threshold’.”
I would feel it safe to say you can apply this to running as well by substituting pace or some other workload for wattage.
I’m still interested to hear a more scientific opinion on this topic as well.
+1
The only thing I would add is that there is no equivalent to FTP in the running world. Between bike & run, speed and pace can be compared absolutely. But whereas “a watt is a watt is a watt” there is no metric that defines your workload while running like Power does on the bike. Pace is good only under certain circumstances (hills, wind, hydration, rest etc). But for now, until they develop a “run powermeter” pace is all we have, thus Functional Threshold Pace is as good a definition as we can get (IMO).
Jack Daniels recommends VDOT testing on a flat course to eliminate these variables.
This month’s Triathlete has an article by Matt Fitzgerald that points out that lactate doesn’t cause muscular fatigue. My question then is, of what use really is lactate threshold? That line is so ingrained in our training practices it’s hard to redefine it. Our inability to sustain activity above this line seems now to be due to a series of factors (brain regulation, other waste products, depolarization) so perhaps we should simply start referring to it as the ‘Sustainability Threshold’. Especially considering the brain’s role as a regulator, it seems now that a lot of athletes may be backing off too early when they see their LTHR when, in fact, their brain and other factors would allow them to go a few beats harder. Add to this the whole matter of the accuracy of LT calculations all based on 4 mml when the rate of lactate removal seemingly varies from person to person so, 4 mml may be pre LT for some and post for others. I am no expert so please correct me on any inaccuracies in the above.
I ask the exercise physiologists out there: Is the lactate threshold dead, and, what do we now call that line?
And this is one of the downsides to heart rate and or power monitoring while competing. I think a lot of athletes have ‘up’ days and/or rise to the occassion on race day and don’t use all that they could have and diminish their race performance. If we are comfortable using perceived exertion we can have those standout performances sometimes.
there are at least 15 different definitions for lactate threshold/anaerobic threshold /mlss in physiology literature. There is also a very wide range in people’s understanding of lactate production and consumption. It’s a bit of a mess.
The fact remains that LT correlates well with endurance performance.
As others have posted, FTP (60min) is a very good approach. In the swim, a 30min TT or 3k TT is commonly used - there’s another thread on the front page right now about this. For running, a 10k race is a good measure for most, although a 60min TT or 10miler is probably better for faster runners with more years of training behind them. Not surprisingly, these measures correspond very well with endurance performance too.
The field tests are IMO the best way to go. But understanding the underlying physiology never hurts.
whereas “a watt is a watt is a watt” there is no metric that defines your workload while running like Power does on the bike. Pace is good only under certain circumstances (hills, wind, hydration, rest etc). But for now, until they develop a “run powermeter”
I don’t think runners really need such a device. Soccer players, maybe, but not runners.
At what people call LT, Lactate does accumulate but it’s because we aren’t able to use it as fuel and it’s not a byproduct from the fuel the muscles are using.
I’ve read the exact opposite on both of these points.
“Since lactate does not cause fatigue, its clearance from the blood depends on the body’s ability to use it as fuel. The body not only tolerates lactate, but at times prefers lactate over glucose as an energy source.”
I dumped the second post cuz I just don’t have my notes and feel it should be answered by someone with a bit more experience. I didn’t take it as a personal attack.
I can hold my 10K effort/intensity for longer on the bike than I can for running.