Tuesday, July 6, 2010

Lactate Threshold Testing

One of the most frequently requested tests at the Performance Lab is for "Lactate Threshold Testing". Here's a quick primer on what it is and how to do it better:

Human nature is to use the tools available for the results we are trying to achieve. What I leanred early on in the couse of bicycle repair is that there are a few specialized tools for the job.

One of the tools that I am calling into question is the hand held lactate meter.

But first, a bit of exercise physiology:
When you are exercising at a mild to moderate pace, you are using oxygen to help you burn carbohydrate and fat. As your intensity picks up, you recruit more muscles and eventually exceed the ability to exercise in the presence of oxygen. When this happens, you start to develop lactic acid in the muscles.

Although lactic acid has been portrayed as the bad guy because of its affects on the exercising muscles (cramps, fatigue, burning), this is only half true. Lactic Acid contains two components, lactate and acid. While it is true that the acid component probably causes the symptoms just mentioned, the lactate is recycled into glucose, a fuel that the muscles can use for energy.

So, lactate gets recycled, and what causes our symptoms and accumulates is the acid.

Then why do many people use LACTATE meters to determine the ACID threshold?

It's a cheap tool.

But it only goes so far. In fact, depending upon how robust your ability to recycle the lactate is (known as the Cori Cycle), testing for lactate accumulation may be way off base.

Each molecule of acid is buffered by a molecule of bicarbonate, which is then broken down to carbon dioxide and water--a direct one-to-one correspondence.

That's why I prefer to measure carbon dioxide released, it gives a much more accurate picture, albeit much harder to measure.

Anaerobic threshold testing is one of the many reasons to choose The Performance Lab powered by Rothman Institute.

No comments:

Post a Comment