Some people run away when they hear the term 'lactate threshold,' but you don't have to! Even the recreational endurance athlete should understand the concept so that they can plan their training more effectively. And while the best way to know what your LT is to get tested with a blood lactate test, understanding the concept and the approximate effort levels associated can help you get faster.

I'm going to explain LT in a way that I hope everyone will be able to understand. That's my goal, anyway. If something in this post doesn't make sense to you, please ask a question in the comments so I can clarify it.

Lactate isn't this evil thing that causes soreness the day or two after exercise (aka DOMS - delayed onset muscle soreness). Blood lactate levels return to normal pretty quickly after intense exercise. Instead, lactate is part of the metabolic pathway that our muscles use for energy. Lactate is fuel. Lactate part of an acid (lactic acid) and produces H+ ions, and it is thought that these H+ ions are what might cause the discomfort in our legs when we run or ride hard. Lactate with an H+ = lactic acid. Had to add that as I was a chemistry major. The key thing to note is that lactate is fuel.

The faster we go, the more lactate we produce so our body can keep up with the energy demand. Too much lactate production, however, and we can't use it fast enough. Then it accumulates. Our bodies don't like that and to counteract lactate accumulation, we are forced to slow down. Ever started a run or ride, especially with a group(!), and perhaps you were pushing your pace just a little bit, and then all of a sudden your body said "no more" and even though you were breathing hard but not super hard, you just had to back off to an easier pace? Nutrition & hydration errors aside, there was a good chance that pace was above your threshold, you accumulated too much lactate, and your body made you slow down so it could clear it. 

The point where your body starts to produce more lactate than it can handle is your lactate threshold. Knowing where this point is can really help your training become more effective. By doing specific workouts you can teach your body to be more efficient at clearing lactate and to be able to handle higher levels of lactate. Specific training will also move your threshold up to faster paces. The end result will be to handle a sub-threshold pace (whatever that might be for you) for longer and also just be able to go faster. This is typically the goal of most endurance athletes.

So how do you figure that out? The best way is to get lactate threshold test. (I offer this service for $150 for the bike and run and can test at Boulder Running Company, Cafe Velo, and Vital Personal Performance Center, or on an outdoor track.) Getting tested allows your specific training zones to be determined so that your easy workouts really are easy, and your threshold workouts are where they need to be. By the way, it's better to be just under your threshold to get improvements than over. Getting tested allows you to know exactly what's happening physiologically. It also gives insight to which areas (endurance, threshold, speed) you might need to focus on depending on your goals.

Above is a graph from an LT test I did for an athlete earlier this year. Lactate production isn't linear. It typically holds steady at easier paces, creeps up as you get closer to threshold, and and then jumps big time once you cross your threshold. The shape of your curve provides valuable physiological information!

If you want to ballpark it, you can do your own graded exercise test and make some notes on changes in breathing that you experience. It's best to have a metric such as heart rate in addition to pace and/or power to associate with this. First warm-up for at least 20 minutes really easy (and I mean really easy!), and then once you are good and comfortable, start increasing your pace every 5 minutes. If on a bike trainer, just shift up a gear. Watch your heart rate and aim to increase 5-10 bpm for each stage. Your heart rate should settle in after the first couple minutes of each stage.

You want to get about 5-7 stages so just make sure you know your window and adjust effort/heart rate increase appropriately. Make a note of the max heart rate of each stage and pace/power, as well as your perceived exertion (can use a 1-10 scale, 1 being standing around, 10 being max/your all out sprint). Heart rate monitor/GPS watches/bike computers often make the data pretty easy to record. You don't have to go to an all out effort, but once you are on the stage that you don't feel like you can handle 5 minutes at a faster pace, you are on your last stage.

Note the pace/power/heart rate that your breathing shifts from comfortable to being labored (and pretty audible). It's around here and the rate of perceived exertion of 7 where your lactate threshold might be. It's usually a kind of hard, but not super hard effort.

Once you've estimated the heart rate and/or pace/power of your threshold, you can set up workouts where you spend time there or just slightly under for specific intervals. Depending on your fitness, you might start with 3-4 four minute intervals, with about half the time as a rest interval. Or if you are more fit you could start with 2-3 eight to ten minute intervals. Do no more than two of these a week, one is often sufficient depending on the other training you are doing. Gradually build up over time, increasing the duration of the interval and/or also decreasing the rest interval. Also make sure your easy and base endurance workouts are well below this pace.

Every so often you will want to repeat the test to check your improvement. 

There you have it! If you want to know more about setting up training zones for effective training, I have a series of posts I wrote last year on my coaching blog. Here's a link to the first one.

I hope you learned a little something from this. Please ask me any questions you might have in the comment section.