Reposted with proper formatting:
yes it is, it's a product of the reduction of pyruvate.
I'm not, but I'm sure it won't stop you from saying so.
this isn't an either/or situation, lactate is produced from pyruvate...not as well as.
I already covered this earlier. Glycolysis produces pyruvate and ATP. Pyruvate can be used to continue glycolysis but it will consume a new glucose molecule in the process. Lactate is formed from the reduction of pyruvate and can no longer be used in the anaerobic production of energy. The key difference between lactate and pyruvate is that lactate MUST be oxidized to be usable in energy production while pyruvate doesn't.
Another pseudo-scientific term...'aerobic fuel'.
Lactate cannot be used as-is as a fuel, it requires oxidation.
To your pseudo-scientific term 'aerobic fuel', I'm assuming you mean they can both be processed in an oxygenated environment, and yes they can, and this takes us back to aerobic base building, and once again the ability to utilize and process oxygen.
Key point to remember, when pyruvate is used to prolong glycolysis, it uses up more glucose to produce ATP/energy. The process is fast but expensive, consumes glucose and glycogen quickly and cannot be sustained on it's own for very long (you get less than 2 minutes worth without the introduction of external oxygen). When lactate is produced, oxygen MUST be utilized to process lactate back into a usuable fuel. Lactate exists as the end product (along with the resultant ATP) of anaerobic energy production. If you build the resources of oxidation muscle tissue and mitrochondria, you provide the ability to continue to break down pyruvate (and, through an extra oxidative step, lactate) into addition ATP without consuming additional glucose/fuel, but this can only happen with a new source of oxygen...the oxygen you draw in and process and you must have the proper development base to do it effectively.
You keep wantijng to conviently skip around the role oxygen plays in energy production. Anaerobic energy production is not sustainable on it's own and relies heavily on oxygen based metabolism to continue. If you have a strong aerobic base (capillary density, mitochondria density, etc.) you can produce more energy without consuming more fuel. If you have a poor aerobic base, you will consume your glycogen/glucose resources much quicker with lower net energy production. Good if you're a sprinter, bad if you're a marathoner.
Take which ever path you want, it's all in how you train and what you expect from your running.