Blood, Sweat, and Lactate

This report filed - February 15, 2007
Jimmy Archer

As an athlete what is the single most important piece of equipment or information you can possess? What is the one thing that will best help you achieve your goals?

In this age of heart rate monitors, power meters, high tech gear, and professional coaching the choice of what will best help you to reach your goals is virtually unlimited. However, the fact is, without a good lactate test all the gadgets and coaching in the world are useless. Ok, their not useless, but their usefulness is greatly diminished.

This morning I got up early, had a light breakfast, grabbed my shoes and running gear and headed into the cold. However, this wasn't going to be my average everyday run. Today I was headed to the Boulder Center for Sports Medicine (BCSM) to have a lactate profile done.

A lactate profile test is vital to any athlete regardless of their level. Pro to beginner, everyone can benefit from this test. The test can be performed on the run, bike, or even swim and should probably focus on your current weakness. The test is not terribly expensive, usually running around $100 and is offered across the country by hospitals, training centers, universities, and physiologists. Whether you plan to use every piece of technology available or nothing more than your watch and how hard your breathing everyone will learn how to train from a lactate test.

When I scheduled the test, BCSM Coordinator of Sports Science, Neal Henderson, had instructed me to prepare for this test just as I would for a big workout or a race. Be sure to rest the day before, eat well, and make sure I was hydrated. Basically, be serious about it.

One stage to go and I'm starting to feel it.

photo: Jimmy Archer

As soon as I walked into the lab I was weighed, measured, given a heart rate monitor and put on the treadmill for an easy 20-minute warm-up. I was asked to guess what I was capable of running a 10k in right now. I was told to be serious and not try to impress anyone, my answer would determine the pace at which we would start, and honesty would improve the overall accuracy of the test. Besides, BCSM has tested the likes of Olympic triathlon silver medalist Bevan Docherty, Tyler Hamilton, and world-class runners, triathletes, and cyclist from around the world, so trying to impress these guys would be difficult at best.

As I warmed up I was told what to expect. We would start off easy, about 70% of my assumed 10k pace. (This starting point was determined by my answer to the 10k question as well as factors based on my age, weight, and performance level.) I would be doing 4-minute stages. At the end of each stage I would be asked my rate of perceived exertion or RPE, an impression of effort based on a 1-10 scale. I would also have my finger pricked and a blood sample would be taken and analyzed. Then we would move on to the next stage, increasing the pace by 0.4 mph. As I ran my blood would be analyzed and my lactate volume calculated. We would continue with these stages until my blood showed I had started to accumulate lactate.

Without getting too scientific, lactic acid, or lactate, is produced when the body is not operating at its highest efficiency and is not fully aerobic. Our cells use aerobic or oxidative glycolysis to produce energy. If the level of effort is high enough the cells cannot produce energy fast enough and must resort to the faster but less efficient non-oxidative glycolysis thus producing lactic acid. This is often referred to inaccurately as being anaerobic. At low enough levels our bodies can process the lactic acid and keep cells operating efficiently. However, at a certain point, called Lactate Threshold, the body can't keep up and lactate begins to accumulate in your muscles. At this point you're on a slippery slope and you won't be able to maintain that speed and intensity much longer.

During my test I could feel the changes in my legs over the stages. At the start I was joking and talkative. I was out for a jog and having fun. After several stages I could feel it getting serious. As I reached my final two stages I knew I was getting close to my threshold. Doubts of how much longer I could hold this pace started to surface and I wasn't talking much any more. My left ring finger was a pincushion from where the blood was drawn and I was wearing a fingernail polish of blood (evidently I am a "good bleeder"). The pace wasn't that hard but it wasn't easy either. I knew the benefits I would get out of this test and I was determined to keep going, but I wouldn't be too upset if they told me I was done. Finally, I was told we had reached the end and I was allowed to slow to a jog and cool down while my results were being compiled. After my cool-down I sat down with Neal and we discussed what we leaned and how to apply it to my training.


Benefits of knowing your Lactate Threshold or LT:

* You will know how hard is too hard. You learn what power, heart rate, or RPE equals your personal LT and know not to go beyond that level except in specific hard workouts. This is a level to visit rarely and for specific training purposes.
* Training too close or beyond LT means you will be spending energy recovering not improving.
* Due to increased recovery demands injury risk goes up when training beyond LT.
* Training too close to LT consistently is mentally demanding and can lead to mental fatigue and burnout.
* Race pace for most triathlons will fall at or just below LT. This knowledge can be applied not only to training but to pacing on race day as well, particularly in long course racing.
* Since LT is trainable, testing your LT 2-4 times per year allows you to monitor your adaptation and effectiveness of your training.
* Knowing your values will allow you to train more effectively.
* This knowledge will allow you to effectively use power meters and heart rate monitors.
* Knowing your LT is essential to creating an effective training program.

I only did a run lactate profile test. However, these results can be translated to the bike and swim as well. The translation will vary depending on the individual but a good tester and/or coach should be able to give you appropriate LT values over all three sports. However, the best results will come from testing the specific sport.

Contrary to some opinions, the off-season is the perfect time to do your lactate testing. This is not a test you want to do well on first time out. In my case, I am coming off an injury and am far from my best fitness. However, after testing, I now know the heart rates and power levels at which I will train most effectively. Thus, I will get back to my top fitness more quickly then if I was just going by feel or intuition.

This is precisely the value of lactate testing. A good lactate test will allow you to train more efficiently, make the most of your tools (power units and heart rate monitors), and give yourself and/or your coach the information needed to create a more effective program.

Jimmy Archer is Editor of InsideTri.com and a pro triathlete trying to dig himself out of the hole of injury we all find ourself in from time to time. Contact Jimmy at jarcher@insideinc.com.