aerobic vs. anaerobic: layman's explanation

I'll take a stab at defining the two.

Aerobic running: When you are running at a pace where your body is able to buffer the lactic acid being produced.

Anaerobic running: When you are running at a pace where your body is unable to buffer all the lactic acid because two much is being produced.

aerobic-with oxygen

anaerobic-without oxygen

Here is some clarification. In trying to explain this to my kids, I couldn't. Try to answer this fifteen year old boy's question then, "what do you mean coach, if you didn't breathe oxygen, you would die. I always run with oxygen?

That's the question I am trying to wrap my fingers around and explain to them what means running aerobically with oxygen, and anaerobically without oxygen. This is where I cannot seem to come up with a simple laymans explanation. The kids see runners running, and they see runners breathing. So when do runners run without oxygen? It's not that the runners are not breathing oxygen, it's what takes place inside the body. That is where I need help. Thanks

We never run without oxygen. The word anaerobic is not really the right one. All running is aerobic, the first few seconds use oxygen stored in the muscles and thereafter we use inspired oxygen.

The second poster was partly correct in as far as the old definition of aerobic/anaerobic refers to the buffering of muscle and blood acidosis, but this is NOT caused by either lactic acid or lactate, rather it is caused by the accumulation of hydrogen protons.

Your muscles use glycogen for fuel. There are 2 ways muscles can convert the glycogen into energy. One way uses oxygen molecules (aerobic). The other way does not use oxygen molecules (anaerobic).

Both ways produce energy quickly. The aerobic way produces less waste products. Your body can process the amount of waste being produced and you can maintain aerobic fueling for a long time (hours).

The anaerobic way produces huge amounts of waste products. Your body cannot keep up with the amount of waste product anaerobic fueling produces. In a couple of minutes your muscles will shut down.

Aerobic = lots of energy, relatively little waste product, your body can keep it up for hours.

Anaerobic = lots of energy, lots of waste product, your body will shut down after a couple of minutes.

The point where you switch from one method to the other is called the threshhold. It is trainable. You can push back your threshhold (stay aerobic longer) with the proper training regimen.

Or I could be completely wrong.

no that's about right snowbear. You have to look at the

triphosphate systems as well but it's as good as you can get without going into 500 pages or so.

All this stuff is pretty well explained in Noakes Lore of

Running, on the Peak Performance web site as well.

Think of aerobic exercise as exercise in which there is adequate (enough) oxygen arriving at the exercising muscles to convert fuel (carbohydrate and fat that is in your body) into the energy your muscles need for running. When you are exercising anaerobically, the "an" part means there is insufficient (not enough) oxygen available to convert fuel to energy fast enough to meet your muscles' energy needs, so you break down some fuel (to provide the energy needed to run as fast as you are running) without adequate oxygen. This anaerobic metabolism goes through a different chemical process (in converting fuel into energy, and pyruvic acid and ultimately lactic acid are the result of this process, whereas when the exercise is aerobic, water and carbon dioxide are produced). Actually both aerobic and anaerobic metabolism are going on all the time, but with sufficient oxygen available, the step from pyruvic acid to lactic acid can be minimized. Anaerobic does not mean without oxygen (that would be anoxic); but it does mean inadequate oxygen. I've tried to explain it as I would to some young runners, I hope this helps.

There is always plenty of oxygen available Jack, there is no true anaerobic metabolism in distance running.

Also, to snowbear, Lactate is a very efficient muscle fuel, there are no significant waste products that slow us down, rather a state of rising acidification interferes with muscle contraction.

Thanks for the clarification, Jack. Corrected summary:

Snowbear wrote:

Aerobic = sufficient oxygen, lots of energy, relatively little waste product, your body can keep it up for hours.

Anaerobic = insufficient oxygen, lots of energy, lots of waste product, your body will shut down after a couple of minutes.

The point where you switch from one method to the other is called the threshhold. It is trainable. You can push back your threshhold (stay aerobic at a higher intensity) with the proper training regimen.

You are correct that there is usually enough oxygen available (available was a poor choice of words, but I couldn't think of a better one to try to make it simple). In fact there can be times when there is not enough oxygen available -- block the artery providing the oxygen supply would do it, or introduce carbon monoxide and try to get adequate oxygen available

How much funding would you get for that study Jack? I will volunteer for #2 if you give me an agreeable type of smoke to inhale, but not #1

Actually, now that we know there is normally adequate oxygen available (except for the vessel blockage and CO introduction), I worry that we will have to do all our altitude reseach over again to figure out why we can't do as much aeorbic work at these higher elevations -- must be global warming

Thanks everyone, that will help immensely