Also known as the anaerobic threshold, onset point of blood lactic acid (OBLA) as well as other names, the lactate threshold is the point at which the concentration of lactic acid in your blood begins to accumulate at a great or nearly exponential rate. I have always found the graphical depiction of the blood lactate curve to be the easiest to use in understanding where the lactate threshold point is.
Now the graph above would be the results of a lactate threshold field test I may do with an athlete. In that test I would have them run for 6 minutes at a variety of paces, each of which they can sustain without trouble for the 6 minutes. I may have them run at their conversational run pace, then the upper end of this pace, then their goal marathon pace, a comfortably hard pace and finally an approximate 5K or 10K race pace for a mile or less. Between each change of pace I would make a small prick on their finger and take a drop of blood to find out how much blood lactate has accumulated in the bloodstream. This is the label for the Y axis, the amount of lactate in the blood in milimoles per liter. On the X axis I have plotted their speed at each one of the samples. From this I can draw the red curves you see in the graph above and the point at which the concentration of blood lactate dramatically increases. This is easily noticed as the point where the two black lines inserted into the graph make a point. The information obtained from this test is valuable for all endurance athletes for a number of reasons. Before you spend your hard earned money and energy to perform any type of performance test you need to know what information it will provide you and how you can incorporate this into your training.
What do you learn from a lactate test?
If a lactate test is conducted properly each bout of exercise will be below 100% of you VO2 max effort. Each segment lasts about 5-6 minutes and will maintain a steady state effort after the first minute. Following the last steady state run or ride the athlete will rest for 25 minutes and then conduct 1 all out effort of 60-90 seconds. Blood will be taken 3, 5 and 7 minutes after this exercise to determine the highest concentration developed during the sprint.
If the lactate measurements are taken using this protocol then the coach can estimate the following for the athlete:
1. The point at which the blood lactate first begins to rise above the baseline or resting levels. This is NOT what is commonly thought of as the 'lactate threshold' (as described above). This is simply the first noticeable rise in lactate concentration (quantified as 1.5 mmol/l above resting). A training pace (for runners) and wattage (for cyclists) can be determined from this. As this intensity is well below the heart rate deflection zone, accurate heart rate training zones are also determined from this test. Knowledge of this pace for an individual athlete is a valuable tool for athletes competing in events that last 2+ hours.
2. The pace or wattage and heart rate ranges that will produce the 4.0 mmol/l of blood lactate during steady state exercise. This will tell your coach the minimum pace that you need to produce to be at or above the lactate threshold. Knowledge of this intensity is useful for a wide variety of athletes, as lactate threshold training is needed by athletes in running from the 1 mile to the marathon.
3. The relative anaerobic capacity of the athlete. During the 75 second top speed test following the steady state bouts, the coach will be able to assess the amount of work you can produce anaerobically. Despite its connotations with sprinting and short distance events, training appropriately in this zone at certain periods in your training cycle will increase your chances of improving you aerobic capacity.
4. With subsequent tests the coach can assess improvements in aerobic capacity and if well trained in the testing may be able to identify if these are the result of aerobic development or anaerobic improvement. Follow up tests allow coaches and athletes to monitor training towards a peak event without the need for a potentially distracting competition prior to your goal event.
A lactate test is a tool
A lactate threshold test is to be used as a tool just like a watch, heart rate monitor or cycling computer. It doesn't replace the role of a coach and educated athlete, nor will it simply unveil a training program for you. Lactate testing is best done after an initial base is established. I would recommend the first test be done 12-16 weeks before a goal competition and a follow up test 6-8 weeks prior to your race. The data from this test should be used to build training paces/intensities for an athlete within the context of the periodized training program.
In next months 'Run Smart' article, I will discuss in more detail what lactate is, how your body uses it during exercise and what type of training will improve your lactate usage and resistance.
I have found that discussion about the lactate threshold and it's training often raises questions. I encourage you to submit yours to me at sean@crpusa.com under the subject lactate training.
Long may you run,
Sean Coster
Complete Running Programs offers lactate threshold performance tests for runners and cyclists of various abilities. For more information check out this information on lactate testing.
For more writings on training, motivation and philosophies in distance running visit Sean's blog at www.seancoster.org/runningportland or www.crpusa.com
Copyright 2008 Complete Running Programs - May not be used without permission of the author.
