I'll respond more completely when I have time to go back through all my research notes and cite what I'll point out below, but here are some things you need to take into consideration:
1) If you want to use the terms lactic acid and lactate interchangably be my guest. Personally, I like to be accurate in my viewpoint and discussions on exercise physiology, I'm not going to say "lactic acid" when believe, and the research supports, that lactic acid is never even produced in the body. I also disagree that how you view lactate has no practical implications as far as training.
2) I also disagree, as do many other very well known coaches from around the world in many different sports, that the best approach is to just "increase tolerance to lactic acid" or however you want to look at it if improved performance is your goal. This is really older thinking and newer research and plenty of experience is showing this really to only be the most effective approach in very very short events.
More and more, we are understanding importance of the aerobic energy system, even in sports that we used to believe were glycolytic in nature.
The 400m for by the way, turns out to be somewhere between 40-50% aerobic, depending on which research you look at these days. Even a 100m sprint is 15-20% aerobic! You are totally wrong saying such events are "without significant aerobic involvement"
I've got tons of research on this but you can start here:
Energy system contribution during 200- to 1500-m r... [Med Sci Sports Exerc. 2001] - PubMed result
How about this...
"The aerobic/anaerobic energy system contribution (AOD method) to the 400-m event was calculated as 41/59% (male) and 45/55% (female). For the 800-m event, an increased aerobic involvement was noted with a 60/40% (male) and 70/30% (female) respective contribution.
Significant (P < 0.05) negative correlations were noted between race performance and anaerobic energy system involvement (lactate/PCr) for the male 800-m and female 400-m events (r = - 0.77 and - 0.87 respectively). These track running data compare well with previous estimates of the relative energy system contributions to the 400-m and 800-m events. Additionally, the relative importance and speed of interaction of the respective metabolic pathways has implications to training for these events."
Energy system contribution to 400-metre and 800-me... [J Sports Sci. 2005] - PubMed result
RESULTS: The relative contribution of the aerobic energy system to the 200-, 400-, 800-, and 1500-m events was 29+/-4, 43+/-1, 66+/-2, and 84+/-1%+/-SD, respectively. The size of the AOD increased with event duration during the 200-, 400-, and 800-m events (30.4+/-2.3, 41.3+/-1.0, and 48.1+/-4.5 mL x kg(-1), respectively), but no further increase was seen in the 1500-m event (47.1+/-3.8 mL x kg(-1)).
The crossover to predominantly aerobic energy system supply occurred between 15 and 30 s for the 400-, 800-, and 1500-m events.
CONCLUSIONS:
These results suggest that the relative contribution of the aerobic energy system during track running events is considerable and greater than traditionally thought
Or HERE for a good review
There are very few sports out there, even ones people used to believe were primarily anaerobic, that do not rely heavily on oxidative metabolism for performance, for a multitude of reasons.
This concept is not some "big leap of faith" it has been demonstrated over and over again over the last several years in the reserach and discussed by various high level coaches all over the world. Even the late Dr. Verkhoshansky, probably the foremost authority on strength and power development in history, discussed this principle he called "anti-glycolytic finality" in his paper on training for the middle distances. He suggested this approach in distances as short as 200m.
I would say focusing training primarily to improve glycolytic capacity is only applicable in very short single bout events lasting 30 seconds or less. Other than that, it has limited usefulness because this type of training will reduce mitochondria in the working muscles and in events of greater duration this is not what you want. A much better strategy is to develop a bigger aerobic engine so that anaerobic metabolism can contribute for longer without leading to fatigue.
My experience training top level MMA fighters for the past 7 years also supports what the research shows. I only do very limited amounts of focused glycoltyic work with any fighter who will be fighting 5 minute rounds.
"And even if one were to agree with that (which I clearly don't), you are also saying that, to train the mitochondria's capacity to handle lactate, you need to train aerobically (where they would get zero exposure to lactate, so there would be no reason for such an adaptation)"
I have no idea why in the world you believe that mitochondria don't oxidize lactate as part of aerobic metabolic processes, you're very mistaken here. Lactate production occurs throughout almost all ranges of aerobic energy production, it is just oxidized at the same rate as production and thus there is no net accumulation. The lactate threshold itself is typically defined as accumulation above 4mmol /L, which makes it obvious there is plenty of lactate being oxidized well below that. You need to look more thoroughly at how energy systems work.
Your general understanding of energy systems seems to be based on older research and older lines of thinking that have shown to be incorrect and/or outdated. There are also plenty of training implications based on what the newer research has shown and it's far more than just an argument of semantics. I get literally hundreds of emails and posts on my own site regarding the effectiveness of the approach I use based on this, not to mention the top pros who will tell you the methods I use and my approach to energy systems works.
For anyone who wants to learn more about this, I'd suggest picking up my book, reading through
Lyle McDonad's series on endurance training and joining my site, where Lyle frequently posts as well. I'll also post more research links when I've got the time.
