Sunday, February 6, 2011
Reflections on VO2 Max, Lactate Threshold, Goals, and Priorities
Lately, I have not been at a loss for things to write, but unfortunately, I have found myself spiraling more and more into highly technical topics, so I have been reluctant to post things on the blog. Most of what has been on my mind is physiology. As many of you may know, I have advanced training as an animal physiologist, and I spent quite a few years of my life conducting physiological research. In one way or another, most of that research was related to energetics, and a good chunk to aspects of energetics and locomotion in small mammals. I wouldn't say that makes me an expert on running or human exercise science, per se, but metabolically speaking the energetics of running in a mouse or rat are pretty similar to that of humans. so I have some familiarity with the concepts and jargon that help me sift through all the stuff one can find on VO2 Max and Lactate Threshold and various other things we're all told we have to improve in order to run our fastest.
So much of this information is out there on the internet when people look for it, that I think it can be difficult to see the forest (the whole picture) for the trees (each concept). You see articles that focus on just VO2 Max, or just lactate threshold. You even find articles in which people suggest that one variables is the most important, or should be emphasized over another. For example, I've often heard it said that most runners will benefit more from lactate threshold training than from working on their VO2 Max. While that is true in the limited timeframe of a training cycle for a single event, in the long run (no pun intended), if you want to continue improving, you need to continue developing your aerobic capacity (VO2 Max). The reason it generally doesn't provide the most benefit in the short term is that one very key aspect of our physiology (oxygen delivery rates) takes so long to respond to training, because it requires reorganization of our muscle tissues themselves, not just an increase in the number of mitochondria inside each muscle cell. It requires that muscle tissues be built, and capillary networks through which blood flows to each cell in the tissues be expanded.
Of course, the increase in mitochondria within each cell will help with VO2 Max as well, but without improving oxygen delivery rates (and carbon dioxide removal rates), this can only offer "so much" benefit. But, people are impatient, and coaches need athletes to show progress quickly to keep their jobs and credibility, and the easiest way to accomplish that for the average athlete is interval training and lactate threshold training. When an athletes does these things systematically, they suddenly begin to see some improvements, and that's great... But after a few weeks or months, they begin to level off again and stagnate. That is, unless they are also doing a sufficient amount of lower-intensity longer-duration running.
And I haven't even mentioned strength work, yet.
My point is that a lot of physiological factors are required for athletes to perform at their peak. If you focus on speed work or lactate threshold training when you have been neglecting them, you will see some good, quick results, but don't expect those results to continue indefinitely, unless you are building the required infrastructure with a solid dose of aerobic endurance running (long slow distance; LSD).
To be sure, you do get some of the same benefits from the higher intensity training as you do from LSD training, but think about it... If interval training was enough to be a killer long distance runner, then all the elite distance runners would be doing all their training this way, instead of mixing it up, and shooting for an optimum mix of low to moderate intensity aerobic work, and high intensity work.
So, the real question is: what are you in this for? Are you a one shot wonder, planning just to beat your buddy in next month's 5K race? Or are you in this for the long haul, aiming for continuous incremental improvements through consistent running, for as long as you're able?
I know where I stand on it this, so I'll just keep looking for that optimal mix and while I'll be aiming for the next race with one eye, when I have one on the schedule, I'll have the other eye focused on the lifelong goal of being my absolute best. I just hope I don't go cross-eyed!