Lactate Myth Buster...
ever there was a black art, smoke and mirrors, myth and legend side to
the voodoo and wizardry of cycling, then the world of lactate is surely it.
physiology, by it's very nature, is
a slightly heavy subject. But stick with it, because it's
important that you understand it if you are to truly realise your
potential and make the most of your training opportunities and
written an introductory factsheet on lactate, based on the understanding
and knowledge of the time. Well time's moved on, and this
factsheet is a reflection of the latest understanding and current
thinking on the murky science that is the human body.
Clearing a Few Myths
You will often see used the term
something threshold. Be it aerobic
threshold, anaerobic threshold, lactate threshold, lactic threshold or ventilatory threshold.
Well here's the rub; there is
no lactic threshold! There's no threshold, there's no lactic
and there's no leg burning acid...
Think of a threshold as you would in a house.
It's a mark, a point, a step where you transition from outside the
building, across the threshold, to the inside of the building.
There's a clear demarcation with three states; you are in, out or perched directly on it.
your body doesn't work like
accumulation, during increasing exercise intensity, is a constantly
rising continuum. But lactate isn't just exercise induced. You always have
some (even now while reading this), you just get more of it when you
exercise and when you exercise even harder, you get even more.
While we're at it,
let's clear up another confusion.
It's not Lactic Acid! Lactic Acid is a neutralizing food additive that is
produced from sour milk and used in bakery products, cheeses, frozen
desserts, jams and jellies to name but a few. It won't make you go
faster. It just makes food taste nice.
use the term lactic to describe lactate. It's like using the term
him and her for humans. Yes, we're all human but as you know there
is a world of difference between men and women! Well lactic and
lactate are just like men and women. Similar but different.
Lactate, is lactic acid minus a proton.
It may be semantics, but this is a slightly more in depth factsheet than
others so it's important to clarify. You can also use this
golden nugget of spurious information on your Training Camp debriefs ~ see
our last factsheet!
So there we are; one minute
in and two bombshells. We're
talking about lactate, and we don't cross thresholds.
There are however, depending on the event we're undertaking,
physiological levels of debilitation (some would call them thresholds) which we should not cross. I'll come back to this
a little later.
Finally (brace yourself for a
stunner), when you're
sprinting, or climbing, or hanging on in a crit and your legs are
screaming with "the
burn", that's not caused by lactic acid, lactate acid or any type
of acid whatsoever.
Remove all thoughts of acid from your mind.
The acid theory held sway from an early "frog's-legs" experiment before the
First World War. Voltage was applied to
dissected frog's legs, and ph measurements were taken until the muscle
fatigued. The ph at the end of the experiment was much lower than
the start, showing presumed "lactic acidosis".
The conclusion was that acid was the
cause of fatigue, and the acid was present due to the lack of oxygen to
transport it away. The lack of oxygen was probably due to
the lack of a body (and lungs) being attached to the legs! It took the Lactate
Shuttle work of George Brooks and his discoveries (see end of this
article), from the 1970's up until today, to change
the world's understanding of lactate physiology.
science research and results are now peer reviewed much more stringently
than they once were.
Facts now hold sway over opinion but still the
lactate myth hung on and to some extent hangs on, right up to the present day.
Doesn't make it right though!
And very finally, there's the
Lactate Paradox. It's been found that lactate accumulations in Everest climbers
(high altitude, low oxygen content), decreases as altitude increases.
We also know that lactate is produced when at rest, with more than
abundant oxygen present. So it can be assumed, that lactate
production is not solely oxygen dependent, present or otherwise.
So, lactate isn't acid, it
doesn't make your legs burn, it isn't oxygen dependent and it doesn't cause debilitating muscle
fatigue. Now we've cleared all that up, and confused the hell out of
you, we can move on...
Lactate Come From?
It is now probably safe to conclude that lactate production results from
energy produced through the glycotic energy system. Which means
the energy produced through the burning of glucose, which as you all
know comes from the carbohydrates we eat.
You will all be familiar with
the terms, aerobic and anaerobic.
Aerobic means "with oxygen", anaerobic means "without oxygen". So
your recovery rides should be aerobic and your sprint intervals will
Having said that, it's not
100% of one or the other. Everything we do uses a portion of
aerobic/anaerobic energy to make up the whole. By definition, your
aerobic energy pathways are being used on a sliding scale right up to
When we are
predominantly anaerobic our effort is consuming more oxygen than our
body can supply. Knowledge gained from your own riding should lead you to the
conclusion that this means we must be going fast, or hard, thus burning
lots of glycogen as fuel.
glycogen as fuel, without the required oxygen being present to help
metabolise it, is referred to by sports scientists as glycolysis.
Glycolysis is the process that
feeds ATP to the muscles as fuel. Pyruvate (like car exhaust gas) is the end product of glycolysis.
At submaximal levels of intensity (with oxygen), pyruvate is immediately utilised for aerobic energy, as can
be seen in the diagram above. This is fuel, and energy, for free.
How this happens is
explained in the Anaerobic Capacity
factsheet, it's fairly complicated but it just happens the way ice forming at night, melts
water in the day, and freezes back to ice again at night. It just
happens a lot quicker inside your body.
As intensity increases
(at a differing point for all of us) the molecule (that was previously
returned) misses getting "attached" and loses the chance to become a fuel source.
It now becomes lactate.
So you can see that
lactate comes from pyruvate. Depending on how well we process it
determines at what point it turns from a friend in to a foe. At submaximal levels of exercise it's a fuel.
At maximal levels it's a hindrance.
Your job as a performance
cyclist is to increase the submaximal level at which this process transition takes place,
thereby making yourself more efficient. The person
with the highest wattage/speed/heart rate transition point (the red
line) will probably be
the rider you've been chasing for the last hour.
So how do you get to make this little molecule
turn back in to glucose (fuel for free) and stop it becoming
Having previously said there is no such thing as an "anaerobic
threshold" I'm now going to have to use the term because it's a term
you've all heard and probably understand. But I'll expand on it a
We all use the term
"threshold." But for all of us it has a different meaning. Someone riding 10
mile time trials will ride at a different threshold to someone riding a
25 or 100 mile TT, or someone climbing a mythical mountain in a seven
hour sportive. So we can see that the term "threshold" is relative to you,
your current level of fitness, and the event you are riding.
Using the common
understanding of the incorrect term "anaerobic threshold", it can be assumed that a 10 mile
TT rider will ride just above it; a 25 mile TT-er will be just on it;
and a 50 mile TT-er will be just under it.
The "anaerobic threshold"
is around the intensity where lactate production is equalled by lactate
removal. Again, the red line in the chart above.
At around this
point you could say lactate production and removal are "in balance".
When they are, you have a nice stone tower. When they're not, you
have a pile of bricks.
terms are different from a physiological level, it's around this
perception and "feeling" that we begin the onset of blood lactate accumulation (OBLA).
The OBLA is the point where we start producing lactate quicker than we can remove
It's more of a mouthful than anaerobic threshold but it is descriptively
correct for the physiological process that's happening within our bodies.
If we go any harder we will
begin to accumulate lactate. We can
sustain just above this level for up to 30 minutes before it becomes detrimental to
onward progress (hence the 10 mile TT reference above). See the Cori Cycle at the end of this factsheet for
the reason why.
And to add even
more confusion, we have Functional Threshold
Power (FTP) to consider. This effort, by
definition, lasts for an hour so it must occur at less
power than OBLA.
for most of us to ride a 10 mile TT at just above OBLA but I would suggest you wouldn't want to try to climb the Tourmalet
at the same level of effort.
Because this level
of effort (power/heart rate) represents
the lactate balance, some people call it the lactate threshold, or
lactic threshold. As explained above both these terms are
technically wrong but they've
all become interchangeable in the wide-ranging lexicon of cycling.
They are physiologically different but to the masses, they mean the same
if you want to improve as an athlete, you need to find the level just
before the lactate balance point. This is now referred
to as your maximum lactate steady state (MLSS). Which
is obviously the highest speed/power/heart rate at which you can ride where your
body makes best use of the lactate you are producing. At this
lactate works for you not against you.
Armed with this
information, you can now train to improve your power output at MLSS and
drive your self limiting OBLA red line closer to your genetically gifted
VO2max blue line.
Tests to determine lactate accumulation are (providing you've spent a
couple of grand on equipment) relatively easy to undertake.
You (the athlete) pedal, while I (the sadist) ramp up the pressure until
exhaustion and measure your blood lactate at pre-determined intervals as we go.
It used to be assumed that
the threshold was when the blood measurement went above 4 millimol of
lactate. But we are all different and 4 mmol for me could be a very
different feeling to 4 mmol for you.
The current recognised way of defining an
individual's lactate turning point is when two consecutive measurements
increase by 1 mmol or more. It doesn't really matter what
the number of the measurements are, as long as they slowly (and sustainably)
curve indicates that the body is utilizing and recycling lactate as
fuel as fast
as it's being produced. Once a "+1mmol ramp" appears on the graph it
demonstrates that the balance point is being approached. When you
get two +1 jumps in succession, it's safe to say the balance point's been reached and breached.
we've now identified the OBLA, we keep going with the ramp. We
know further effort will just
bring about the end sooner than you'd like but we carry on until
exhaustion as we get important VO2max information from the same test.
your value of the test and proves just how quickly the end does come when you press too hard.
For some this
information, and the closeness to fatigue from a point of "relative
comfort" is a real eye-opener. This feeling, perception and
experience is often the point in their cycling career at which their
understanding of training principles, and their subsequent racing
results, moves to the next level. It can be a real epiphany.
What's the Point?
By measuring lactate
accumulation an athlete can establish their current point of exercise excellence.
The point at which they can just sit there and, potentially, cruise all
your MLSS point is at a higher wattage than mine, then guess who's going
to be giving, and getting, a kicking out on the road.
The resulting conclusion of
all this drivel is that you should be looking to pinpoint the level of
effort that is right at the edge of your maximum lactate steady state
production/utilization. Once you've done that you can go about
Working in Practice
If you want a real live example
of how this works then we should look no further than the world of
IronMan athletes (like riding partner Richard Davy on the right) and
I'm sure you've seen the scenes at the end of the London Marathon or an IronMan event when
the skinny leaders come across the line utterly exhausted.
Well here's a
surprise for you. Their lactate measurements at the end of the
event are stupidly low. The good ones cruise at 1 mmol above their
baseline for the majority of the event. And ramp up to their
maximum lactate steady state level as the race moves on. And for
the swim and run they haven't even got a
athletes run right on the edge of their MLSS, remaining aerobic, using
predominantly fat for fuel, saving carbs and recycling their pyruvate to
get their race winning fuel for free. When did you last see a marathon runner
throwing a load of power bars and gels down their throat in a race?
We all try to
race like a 100 metre sprinter. We should be thinking
with an ultra-endurance athlete's mindset if we want to be more successful
in our quest for greatness. At least for
99.9% of our chosen event.
Obviously if you wan to improve your performances through developing
your lactate metabolism, a Lactate Performance Evaluation is required.
This test will determine your individual Onset of Blood Lactate
Accumulation wattage and heart rate.
And that opens
up a whole new world of training opportunities that we'll cover next
Lactate is a by-product, not a waste product, of exercising.
It should be seen as your friend not your enemy. Although, as with all
things in life, everything in moderation.
Lactate is an
output of anaerobic exercise and an input for aerobic exercise.
When you ride with the grey area that's the boundary of both, you're
potentially in to a free ride. The person that maximises their
wattage at this boundary is on to a winner. Quite literally.
If you can
produce the same or more power with less resultant lactate, you're
becoming much more efficient as a cyclist. Cycling is an endurance
sport and efficiency is key to conserving your valuable energy
resources. No use being the best sprinter in the race if you're
not there at the end to use it.
At the point
just before the Onset of Blood Lactate Accumulation is the
Maximum Lactate Steady State level. This is the
point you want to move up your power and speed, and down your heart rate, scale.
Measure your OBLA, train to improve your MLSS, go off and win some time
trials, stay away in a break, or climb like a god. How hard can it
Lactate Testing & Training Part II
If you want to get really heavy, here's some additional info that adds
depth/confusion to that already created above.
Brooks' Lactate Shuttle
The reason we "carbo-load" before a big event is so we can saturate
our liver and muscles with energy giving glycogen to help us through our event.
The multi-functional liver (through the Cori Cycle (see below)) is capable of supplying glycogen, via the bloodstream, to
wherever it's needed within the body. Individual muscles, however, can only
use the glycogen that is embedded within that particular muscle.
Once it's in the muscle it can't leave to go anywhere else.
So when you're
climbing, your glycogen-full shoulder and arm muscles are incapable of sending any spare
fuel to your energy depleted legs. You're dying
on your ass and your arms are full of energy giving and race winning
glycogen that your legs can't utilise. How rubbish is that?
Lactate is a
different animal and operates in a different way. Remember that
lactate can be used as fuel. So this bit is quite important.
special transporter proteins who's job it is to take lactate from the blood
and deliver it to muscles around the body. This has the
dual function of lowering localised blood lactate concentration (by
dispersing it around the body) and bringing much
needed fuel to muscles that require it.
submaximal effort "supplementary muscle fuelling" happens far quicker
than you eating an energy bar and waiting for the
digestion process to
kick in and deliver glycogen from the liver. This is the reason we
need to make lactate our friend and to embrace it like it is the wind at
wattage/heart rate where this shuttle is working at its optimum
efficiency is important to you as an athlete. It could be the
difference between a top ten and a podium place in your target event.
The Cori Cycle
The Cori Cycle is a training partner of the Lactate Shuttle. It
has a different function but it's complimentary to your understanding of
lactate and going faster.
The Cori Cycle
describes the metabolic pathway that uses our blood to transport the
energy by-product lactate to the processing marvel that is our liver.
Once in the
liver, the lactate is converted to glycogen, then to glucose through a
process called gluconeogenesis. The blood is then used to
transport the glucose back to the muscles. Once in the muscle it
converts back to glycogen for fuel, is used and if you're
still going flat out is converted back to lactate. Simple!
cannot be sustained indefinitely. You don't get something for
nothing in this world; there's a price to pay for everything.
cleverly attaches two stored ATP molecules to the incoming lactate to
change it to outgoing glycogen. But it costs the liver six ATP
molecules to be able to do this. So the liver suffers a four
molecule deficit for each "upgrade" it carries out.
Sooner or later
(around 30 minutes depending on pre-event hydration and fuelling levels)
the energy giving stocks will be exhausted. When that happens, you
bonk, you stop.
The only way to get back in to ATP credit is to back off the intensity
until you reach a level of positive balance. From there, you have
to surf the wave that is lactate balance if you want to get to the end
of the day before the time cut-off.
Finally, Why do my legs
The burning in your legs is
caused by muscle polar and de-polarisation! It's to do with
ionisation not acid. We'll cover that another day.