At what point does aerobic turn to anaerobic?

[ArchAngel777]

Just as the title suggests. I was reading up on the 1 mile run and there was a rather obnoxious expert conversing with another member of a board while doing some research. It was said that running the mile is 90% aerobic. I am not sure I quite believe that, but perhaps because the terms are not so cut and dried, at least in practice.

For instance, I could run a mile in about 6 minutes and then I am completely out breath, gas, muscle strenth. I consider the exercise anaerobic because it isn't something I can sustain for a long time, thus I have an oxygen deficit until finally it is all depleted and I have to give up. It isn't a lack of energy, but a lack of oxygen.

On othe other hand, if I were to run 7 minute miles and could run three of them, I would say that falls under aerobic, because it is a much longer duration.

So at what point can we consider something Aerobic? Is there really a set standard for it? If you have $5,000 in the bank and lose 100 every second, how long before you are broke? 50 seconds... If you lose $50 every second, how long? 100 seconds... $25? 200 seconds and so on... My point is that if there is a decifit of oxygen, doesn't that constitute anaerobic?

Would like some thoughts on that...

[russianwol]

Hmmm. I'm sure Wikipedia has good definitions for those terms.

[droman]

anaerobic usually means high intensity. such as short sprints. although i see why you made the comments you made above. i also believe it has to do with VO2 max which is the intensity of running bascially. i think anaerobic is like over 80% or so

[Anthony]

http://www.crossfit.com/cf-download/CFJ-trial.pdf

Scroll down until you see the chart titled "Typical Percentage of Training Time..."

[ArchAngel777]

Thanks for the post Athony... One question though, it says the following in a quote...


Of the three metabolic pathways the first two, the phosphagen and the glycolytic, are "anaerobic" and the third, the oxidative, is "aerobic".

Ok, makes total sense so far... Then it says a bit further down...


As an example the sprints at 100, 200, 400 and 800 meters are largely anaerobic and events like 1,500 meters, the mile, 2,000 meters, 3,000 meters are largely aerobic.

Ok, this is where it doesn't make sense... Look below at the graph for the 1 mile run.

20% is phosphagen, 55% is glycolytic and the remaing 25% is oxidative. Thus, the mile run is largely anaerobic, not aerobic. If we look at the 3,000 meters (2 mile aprox) we also can see that it is largely anaerobic and not until we hit the 3 mile run do we see the aerobic overtake anaerobic.

That graph and the article in about crossfit in general was a good read. I really enjoyed it... Suprised I never seen that on their website when I have researched it.

[MixmasterNash]

1) It depends how fast you run...
2) I think that graph is wrong. Anything over 2 minutes is almost entirely aerobic.

[Anthony]

The graph was referenced in Supertraining but Siff does make note that some of the examples are off. I can't remember the reason why, but something tells me it was how they were tested.

And mix is right. Generally speaking:

0-20 seconds = phosphagen
20-120 seconds = glycolytic
120+ seconds = oxidative

[MixmasterNash]

The graph was referenced in Supertraining but Siff does make note that some of the examples are off. I can't remember the reason why, but something tells me it was how they were tested.

There is also the fact that you can go anaerobic during an aerobic activity, such as a 2 miler, or even a marathon. This usually happens at the end of a race, and is known as the kick.

People performing aerobic activity probably do go anaerobic at times, but as the correct energy systems timings indicate, this can only last for a short time. A key concept is that the energy systems can operate at the same time.

Again, this also depends on the person: an elite miler is probably operating beyond aerobic threshold for more than half of the the mile race.