Lactic Acid: Friend or Foe?

         As a recreational or elite athlete, weight trainer or cardio junkie, I'm
sure that, at some point in your fitness careers, you've experienced that
intense burning sensation in your muscles after some higher tempo running, or at the end of your intense set of biceps curls. 

        This apparently invisible barrier to muscular contraction has traditionally been linked to the accumulation of lactic acid within the muscle cell. Lactic acid (more specifically lactate) is a natural byproduct of carbohydrate metabolism during intense exercise, and is even produced to a small degree during rest. The difference is that, at rest, the muscles are able to clear lactate at a rate that exceeds its production and, therefore, no appreciable buildup occurs.

        When exercise intensity reaches a level to where oxygen can no longer be used to produce energy (e.g. sprinting), lactate accumulates as carbohydrate is broken down to supply "quick" energy. Unfortunately, this cannot be sustained for long before the concentration of hydrogen ions (H+) - not the production of lactate - causes the cellular environment to become acidic and impair muscular contraction. These two events happen to coincide, but it is the decrease in pH of the muscle cell that won't allow the muscles to contract, no matter how much we grunt and grimace!

     So, Metabolism 101 aside, give me something I can use, Mike! Well folks, don't despair, because we can all improve our bodies' ability to tolerate this crippling phenomenon. Here's how:
* Endurance training: by gradually increasing our muscles' ability to extract oxygen from the blood at lower intensities, we improve our threshold for lactate tolerance.
* Steady-state training: exercising at a level that is perceived as "hard" or
"somewhat hard" over moderate distances will also favorably shift our
lactate threshold.
* Interval training: alternating between short bursts of intense work (15 to
120 seconds), and rest periods of equal or shorter time, will improve the
body's tolerance to higher levels of acidity.

Mike Wilson is a Strength and Conditioning Specialist with PURSUIT Training
and Rehabilitation, located in the Cloverdale Athletic Park (168th St. and
64th Ave), which is currently offering Speed, Agility, Quickness, and
Explosive Power programs. Please call 604-574-2895 for details.

Mike Wilson

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