Ross A. Laird

I made it through Easter, but barely. I seem to have a limitless appetite for bacon. And chocolate, of course. But this week I worked hard at the gym (twice), and I also added some aerobic training at the beach. In addition to my strength training regimen (which is primarily anaerobic), it's going to be important for me to improve my aerobic fitness -- and, by extension, my lung functioning. Whenever I get sick, it's almost always in the lungs. I tend to blame my chain-smoking mother for this, but it's also due to my generally poor aerobic fitness. So, today I began a small amount of interval training while completing my hour-long walk. Basically, interval training involves running for a short while, walking, then running again. Typically, a good place to start is with jogs of thirty seconds interspersed between stretches of walking for three or four minutes. I did not time myself today; instead, I focused on listening to the amount of exertion my body seemed comfortable with. This translated into short jogs of a minute or two, with a few minutes between. Interval training works: the research is clear about this. And, as if on cue, this appeared in my news this morning:

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.
In a paper in press for the American Journal of Physiology - Endocrinology and Metabolism, published online in January, Brooks and colleagues Takeshi Hashimoto and Rajaa Hussien in UC Berkeley's Exercise Physiology Laboratory add one of the last puzzle pieces to the lactate story and also link for the first time two metabolic cycles - oxygen-based aerobic metabolism and oxygen-free anaerobic metabolism - previously thought distinct.
"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.
"The world's best athletes stay competitive by interval training," Brooks said, referring to repeated short, but intense, bouts of exercise. "The intense exercise generates big lactate loads, and the body adapts by building up mitochondria to clear lactic acid quickly. If you use it up, it doesn't accumulate."

My previous experiences with running have made me a convert to the Jack Daniels (really, that's his name...) method. The Daniels book is excellent. Here are some of his ideas:

• Run as though you are on eggshells, lifting your feet off the ground only slightly, taking the jolt out of your joints;
• Take small steps;
• Run at about 180 steps per minute;
• Exert yourself less than you think you should (for me, it's about 150 heart beats per minute, slow enough to carry on a conversation);
• Train using intervals
• When you can run for twenty minutes at the threshold pace, use this as a baseline for longer runs of an hour or so;
• Once in a while, do a "maximum exertion" run, but don't do this often;
• Keep going...

I highly recommend the Daniels book. It's what I'll be using as I move forward with the aerobic part of my program.