part 3/4 of this series
When your muscles make energy they wish they could do it all with oxygen. But, alas, sometime we push ourselves and that is not possible. Sloths seem to have perfected it, nice slow easy movements, very efficient. Anyway, what happens when we need more than can be provided by oxygen alone is that the body takes a short cut. It turns glycogen into pyruvate to get at some of the quick energy, and then would like to finish taking the pyruvate to another process to release the rest of the energy using oxygen.
When that cannot be accomplished, that is there is no oxygen lolly-gagging around, it sticks it aside turning it from pyruvate to lactate. Lactate can still be combined with oxygen to get the last drop of energy out but it can also go mobile in the bloodstream to get taken care of elsewhere. The process to get it turned to energy is called the lactate shuttle. Lactate does not sit in the muscle but is whisked away in the blood and is turned back to glycogen by the liver, or ideally some oxygen shows up and the lactate shuttle thing is used right there in the muscle. If it cannot be taken away quickly enough it will build up. Lactate is not Lactic acid, but if lactate builds up it will be turned into lactic acid. The difference between the two is a hydrogen ion. Just one of those chemical things that if you get too much of something there is a process to do something about it. So ideally your circulatory system takes it away to be filtered out. When it builds up it turns to lactic acid, creating acidic environment for the muscles, called acidosis, that hurts and fatigues the muscles and makes them stop eventually because the process for making more energy does not do well in an acidic environment. It is a protection mechanism so we don’t blow ourselves up.
The deal is you want to have a high level of lactate removal so you can work harder. The better job you do it the closer to VO2Max you can endure. Your lactate threshold always comes before you hit VO2Max, but how close you can get is an individual thing. The worse your body cleans this stuff out the less you can work. This is of course speaking of long term exercise like what is done by someone doing a triathlon, or a marathon or a century (100 mile) bike ride, or a swim across the english chanel… you get the picture. If you only need to work for a short period then this is not anything you need to worry about, you can curl up in a ball and payback the oxygen debt if you prefer once the 50 meter sprint or mile race is over.
If you want to go far… faster, you need to work on this lactate threshold. There is of course testing, and it measures the buildup of lactate in the blood. The test for lactate threshold simply measures your blood levels of lactate and once it starts to build up, this is considered your lactate threshold. A lab is your best bet if you want accuracy, but then we are talking several trips cause you are trying to improve it. The simple test is to get a treadmill and make like Roger Banister, that is experiment with your own body.
After you got the idea of the concept it will sort of become obvious how to test it on your own. For example, if you can run 8:30 miles one after the other and not have to stop before say 5 miles but could keep going longer if you really wanted to, then you can safely bet that you are not operating above your lactate threshold. But if you start it out and after 3 miles have trouble breathing and keeping your mind set on holding that pace and eventually slow down a bit then you are probably above the threshold. As a rough guide it seems to happen around 85-90% of your maximum heart rate but will be different for everyone.
The way to train yourself and improve your lactate threshold is to give your muscles a lactate bath and let them figure out how to handle it better. That sounds scary or unsafe, but we are talking about training hard, at 85-90% of your maximum heart rate. Run with a group that is faster than you and you feel like you are dying each day you run with them and wonder if you can make it. Your muscles and blood vessels will figure out how to do a better job of it cause they wont like it.
So keep in mind I am only trying to share the concept of lactate threshold here -the how it works and why it needs to be improved. It is as simple as thinking of it as a measure of how well your muscles and circulatory system can move lactate first out of your muscles and then out of your blood. It needs practice to get better. It can be like an interval workout as long as the rest interval is long enough to clear out all the lactate, go crazy hard for a minute and then move to below your threshold speed so you can attain an active recovery then once you are feeling all normal at that pace, do it again. Or it can be a longer workout where you go just above the level for a long period of time. Both of these will help, the interval one with longer active recovery periods will be easier. The longer workout just above the level (say 45 minutes) will also help you to improve your race times when you will be pushing yourself to do your best. By experiencing how you feel and how to push onward you will learn how to push all the chips in near the end of the race. If you never operate there you will likely begin to wonder if you are going to make yourself pass out if the first time you try it is race day.
Here are some links that go into a little more detail, and if you really want to get better testing methods or workouts than I have gone over then you are going to have to go see the google about that.