Bad Wigins wrote:
Aerobic respiration was doing the trick for about 300 meters but greedy muscles demanded more energy than the available oxygen could process, so they turned to anaerobic respiration to burn fuel. Of course, the by-product of anaerobic respiration is lactic acid, a substance which, in excess, is toxic.
is false, completely backwards even. The first 300 is not aerobic. Everyone who runs 800 knows this, or damn well should.
You start out almost entirely anaerobic, and as pH drops, you switch increasingly to aerobic. Acidosis hits late because it takes a while for pH to drop to a crippling level, and because the increasing aerobic respiration acts as a buffer against it. The same hemoglobin that delivers more oxygen at low pH also binds to cations and removes them from the muscles.
The 800m beaks down differently depending on the make up of muscle fiber and training, fast twitch/slow twitch and 400/800 training versus 800/mile. For the purpose of this explanation, I am going to use an 800m specialist, someone who does not have the raw speed (anaerobic system) to excel in the 400, the endurance (aerobic system) to excel in the mile, but has just enough of each to excel at the 800m.
When discussing the 800m we generally talk about it in terms of the first or second lap, but an 800m specialist should look at the 800m in 4 phases.
The first (350) is 'almost' completely anaerobic, it is a controlled sprint.
You can't say the first lap is completely anaerobic because as you approach the first 400 your aerobic system is starting to be engaged just like running a 400m race. The first 400 should feel like running 400m intervals in that you are tired, but could keep going if you had to.
From 350 to 500 is still mostly anaerobic, your still maintaining a sprint posture and mindset. At this point you are trying to be economical, run fast (sprint) with as little effort as possible.
At 500, your aerobic and anaerobic systems are fully engaged, although the race is still about 70% anaerobic at this point. You are thinking about positioning, maintaining your stride pattern and beginning the process of fighting off fatigue.
At 650, the race is about 70% aerobic, your are tired, you are feeling all of the sensations of the business end of a distance race and the lactic/muscle sensations of an all out 400m sprint. This is the essence of 800m racing, this the 800m hurt and there is no way around it.
Coming off the final turn, from 650 to home is about is about competing with your competitors and competing with yourself. You are fighting to maintain form and lift your legs when your body is telling you to slow down and breakdown. There really is no such thing as a kick in the 800m, your last 200m is never going to be faster than your first 200. You want to maintain your form and continue to lift your legs while hopefully your competitors are breaking down and going backwards.
That's basically it.
race never becomes You are