Over the past few months I’ve been particularly interested in learning the science behind running; biomechanics, physiological factors and molecular biological changes…yeah, real geek stuff, but it really fascinates me.
I’ve always been told a good coach can answer the question “Why are we doing this workout.” For example, a coach may say the purpose of today’s workout is to increase your pace at lactate threshold or increase your running economy. Perhaps a better question is, what happens within the body physiologically during and after these workouts that helps make us run faster?
Yesterday morning I had the opportunity to observe an exercise physiologist and a coach while they tested blood lactate levels of 4 elite runners.
Testing blood lactate for athletic performance and response to different training stimulus has been around for quite sometime now. In fact, horse trainers have been testing horses for years and some feel it’s an accurate way to measure performance. Other sports include swimming, rowing and triathlons.
Testing an athlete involves running consecutive set intervals (in this case 800m) at which the pace is gradually increased after each interval. The coach or exercise physiologist will then prick the athlete’s finger, drawing blood after each interval to determine the blood lactate level at that particular pace. Below is an example of test results:
Pace (per 800) Actual Pace Heart Rate Blood Lactate
3:10 3:09 158 2.3
3:00 3:00 168 1.9
2:50 2:49 175 2.4
2:40 2:40 178 4.7
2:30 2:29 185 7.3
The above is what I call a “blood lactate blueprint” for that particular athlete. This gives the coach a picture of how that athlete accumulates lactate in their blood as they run faster and how quickly they can clear lactate from their blood and muscles to reuse as fuel. Once this “blood lactate blueprint” has been established it is now possible to nail down threshold training paces.
The most common threshold workout is the 20-minute tempo, which is often called the anaerobic threshold. Historically, this pace was established when blood lactate hit 4.0mmol per liter and was considered the staple threshold workout. There has since been questions as if 4.0mmol per liter is an accurate lactate level for anaerobic threshold since everyones lactate curve (the picture above) is unique.
Due to recent research, scientists and coaches are starting to focus on multiple threshold paces, which brings us back to yesterday’s test. This coach was particularly interested in a slower pace. A pace that is often overlooked. The goal of this test was to determine a lower lactate threshold. A pace at which blood lactate levels would stay around 2mmol per liter for about 20 minutes. This is a relatively slow pace and typically falls somewhere between anaerobic threshold and marathon pace.
For these athletes this was the second blood lactate test, the first being the “blood lactate blueprint.” The first test was used as a guide to hone-in on the exact pace where the blood lactate levels stayed steady at 2.0 mmol per liter for 20-minutes.
In this second test the exercise physiologist focused on very gradually increasing the pace until a blood lactate of 2.0mmol per liter was reached. Then the athlete ran at that pace for 20 minutes. If blood lactate started to creep up above 2.0mmol per liter, the pace was slowed till it stayed constant at 2.0mmol per liter. (A treadmill was used because the pace could be controlled better then running on a track and was increased in .2mph increments) For the athlete mentioned above that pace would fall between 6 minute and 5:40 pace.
The coach explained that running at this “lower lactate threshold pace” provides a much-needed base for anaerobic threshold and VO2 Max work. He went on to say, without training at this lower lactate threshold pace athletes cannot realize maximal gains when working anaerobic threshold and VO2 Max. One can think of this work as base-building for future anaerobic threshold and VO2 Max work, much like one would base-build prior to starting a training cycle.
The interesting part is because of its relatively slow pace this type of threshold pace can be completed the day before a hard workout without depleting glycogen stores for the next day’s effort thus leaving the athlete still feeling fresh. An example workout maybe an hour run where the first 30 minutes are done at an easy pace then progressing so that the last 15 to 20 minutes are completed at the lower lactate threshold pace.
The coach went on to say we’ve only scratched the surface of understanding and then applying lactate testing in most running programs. Will this type of testing become mainstream in a few years where every aspiring runner will get tested? Will the runner lining up next to you in your next race getting tested? It may already be happening. The exercise physiologist went on to say she has clients of all ages and levels, even high school teams.
For more information or if you're interested in getting tested, feel free to contact me at email@example.com. There is also a great article in Running Times (which is were the graph came from) on this topic that can be found here: http://www.runnersworld.com/race-training/find-your-tempo.