Physically Focused is now offering Lactate Threshold Testing, a highly useful tool for athletes looking to fine tune their training.
What is Lactate Testing?
Lactate testing looks at the amount of lactate in your blood at different levels of intensities.
The data will be pulled together to form a bigger picture on your ability to “control” your lactate levels.
What
is Lactate?
We are always producing lactate because it is a by-product of our metabolism.
We metabolize glucose, a 6-carbon sugar, which can be made from carbohydrates
or from fats. Glucose is sent through our anaerobic system first where
it produces energy and is split in half. These halves can have different
fates:
- If there is sufficient O2 and low-energy demands, like we see from rest
to low-impact cardio exercise, each half have the option of going through
to the aerobic system where they are further broken down to produce lots
of energy.
- If there is not enough O2 with high-energy demands, like we see from
high-impact cardio exercise to all-out sprints, the aerobic system is
no longer an appealing pathway and at the end of anaerobic metabolism
each half will convert to lactate.
- Lactate was once thought to be a dead-end metabolite but now is known to have roles in supporting aerobic metabolism, rebuilding sugars and proteins, and in producing energy itself.
How
will Lactate Testing benefit me?
All endurance athletes, from the recreational to the elite, train to perform
at a high level of power or speed, but those who perform the best do not
necessarily train the most or the most intensely. The
best performers know how to train optimally and to make the best out of
what they have because they know what they have. Lactate, like VO2, is
another individual marker of one's muscular endurance (read below for
the difference between VO2 and Lactate Testing). A lactate profile will
tell you where you are, where you must train, and where you must be before
a major event.
Lactate profiles are used to determine your personal optimal training
zones and paces for long-slow distance, medium distance, and intervals.
In the last weeks before a major event a lactate profile can give you
optimal pacing for your goal.
Why is lactate bad for endurance exercise?
Lactate is not “bad” because it serves very useful purposes but it is
always produced and must be cleared from our blood (lactate is measured
in mmol). This is not the fault of lactate itself, it is the acid (hence
the term lactic acid) that comes along with it that provides a threat
to our blood's balance.
Our blood's acid/base balance is highly regulated so when and acidic product,
such as lactic acid, starts to build up the body will employ defense mechanisms.
First the body will buffer (neutralize) the acidity with CO2 which causes
us to breathe out more CO2. But once lactate build-up is beyond our buffering
system, the muscles will start shutting down as a final defense against
blood acidity.
Lactate is not bad for endurance exercise as long as we can control its
concentration in our blood.
Does lactate cause muscle soreness?
Contrary to popular belief lactate does not cause muscle soreness. Lactate
is cleared from the blood within a few hours but muscle soreness can last
for days. Muscle soreness is caused by microscopic muscle tears and other
nasty responses to strenuous work which is best remedied by taking the
time to warm-up, cool-down, and stretch.
How Lactate Testing Works:
Lactate tests must be specific to the person's mode of exercise, so cyclists
must be on their bikes and runners/walkers are on a treadmill.
Lactate tests are sub-maximal which means we won't bring you up to your
maximum capacity, but are longer in duration than a peak test.
You will begin with a long warm-up (15-20minutes) the moved into a low-impact
first stage.
Each stage lasts 4 minutes with each stage being progressively stronger
then the last. At the end of each stage a drop of blood will be
squeezed out of your ear (very painless) or fingertip and into an analyzer.
We will measure heart rate and your rate of perceived exertion along with
lactate after each stage.
This continues on until your lactate reaches above a level of 4 mmol.
All tests are followed by a full interpretation of results, and everyone
one will receive a graphical representation of their test.
What is the difference between a VO2 test and a Lactate Test?
Aerobic capacity is defined by your cardiovascular fitness and muscular
endurance fitness. A VO2 test gives a picture of your cardiovascular fitness
because it is a test of your ability to utilize oxygen. Lactate gives
a picture of muscular endurance because it is a test of your muscles'
ability to control lactate, a substance that can limit muscular work.
A combination of VO2 and Lactate profiles will give the best comprehensive
picture of aerobic conditioning.
Article by Jennifer Lee
Physically Focused Metabolic Technician
WOODSIDE, CA. • PHONE: 650-851-2705 • ©2006 PHYSICALLY
FOCUSED