www.xtri.com

Berkeley — In the lore of marathoners and extreme athletes, lactic acid is poison, a waste product that builds up in the muscles and leads to muscle fatigue, reduced performance and pain.

Some 30 years of research at the University of California, Berkeley, however, tells a different story: Lactic acid can be your friend.

Coaches and athletes don’t realize it, says exercise physiologist George Brooks, UC Berkeley professor of integrative biology, but endurance training teaches the body to efficiently use lactic acid as a source of fuel on par with the carbohydrates stored in muscle tissue and the sugar in blood. Efficient use of lactic acid, or lactate, not only prevents lactate build-up, but ekes out more energy from the body’s fuel.

“This is a fundamental change in how people think about metabolism,” Brooks said. “This shows us how lactate is the link between oxidative and glycolytic, or anaerobic, metabolism.”

He and his UC Berkeley colleagues found that muscle cells use carbohydrates anaerobically for energy, producing lactate as a byproduct, but then burn the lactate with oxygen to create far more energy. The first process, called the glycolytic pathway, dominates during normal exertion, and the lactate seeps out of the muscle cells into the blood to be used elsewhere. During intense exercise, however, the second ramps up to oxidatively remove the rapidly accumulating lactate and create more energy.

Training helps people get rid of the lactic acid before it can build to the point where it causes muscle fatigue, and at the cellular level, Brooks said, training means growing the mitochondria in muscle cells. The mitochondria – often called the powerhouse of the cell – is where lactate is burned for energy.

This is going to require a 180º change in understanding for many coaches and trainers. Phew!



  1. sh says:

    having run 3 full marathons and numerous smaller races this is BS.
    Steve

  2. moss says:

    Is the comment supposed to be a subtle illustration of the difference between lore and science?

  3. Jammer says:

    Why are people surprised by this? I thought this was common knowledge for at least a decade. Apparently some people don’t read others’ research. CytoMax (an endurance drink) has utilized this knowledge for a long time. It acts as a sort of buffer/transport for the lactic acid helping move it to where it can be utilized for fuel. I used to use it back in the days when I used to cycle a lot and it worked great.

  4. Me says:

    Yeah, I thought this was common knowledge also. One of the things that separates world class endurance athletes from the rest of us is that they generally don’t hit “the wall” (when the body’s glycogen store runs out @ 20 miles in a marathon). They know how to train so they can switch fuel sources.

  5. Zuke says:

    I have my doubts on this as well.

    I mountain bike race competitively and I’ve started taking a supplement called SportLegs. It contains a small dose of calcium lactate and magnesium lactate. The basic theory is that the presence of lactate in the bloodstream tricks your body into thinking it does not need to produce lactic acid so soon and so much of it, hence delaying muscle cramps and fatigue/burn. Several world champion cyclists swear by the stuff and I believe it works for me too. It is a new small company, so I don’t believe they are getting paid big bucks for endorsing stuff that doesn’t work. It’s not a dramatic difference (like taking steroids or blood doping), but any small advantage helps, especially if you’re doing a 24 hour endurance race! If lactic acid was fuel, this stuff wouldn’t work worth a bean and would actually be a disadvantage.

    Perhaps the good professor is confusing increased performance resulting from increased VO2 capacity and muscle strength/conditioning from training as a byproduct of this theoretical lactic acid-as-fuel concept.


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