Lactate Threshold

I received a great question this morning and I thought the response might be of interest to some folks. Thanks to Phil for the questions:

Robb, do you know the relationships between:

1. Oxymetry and aerobic states
2. Oxymetry and anaerobic states
3. Lactate thresholds and HR
4. How to use the combination of a HRM and a real time activity monitor to
Determine health level
Determine fitness level
Optimize fitness performance

Thank you.

Here is my answer:

Now Oxymetry (as far as I know) refers to oxygen saturation, or more specifically the MEASURE of blood oxygen saturation. Unless we are looking at an individual who is training at altitude OR an individual with significant respiratory damage (smoker, pneumonia etc) oxygen saturation and transport is NOT the limiting factor in performance, be it aerobic or anaerobic. We may see a dip in oxygen saturation during say an anaerobic bout of rowing but this is not the limiting factor in performance. Hydrogen ion build up and lack of substrate (fuel) tends to be the limiting factors. Some recent research shows that it is tough to completely deplete the myoglobin in the muscle of oxygen. Oxygen is transported via hemoglobin in the blood from the lungs to the rest of the body but myoglobin in the muscle acts as an oxygen sink for use during activity. If we are unable to completely deplete oxygen at the muscle level it is further evidence that hemoglobin saturation levels are not typically the limiting factor in performance.

Richard Gibbens at Power Running expands on this information. Great site and very well presented. His basic message: get stronger, run intervals, run your RACE DISTANCE AT YOUR RACE PACE. No BS volume phase, etc. If you get stronger, if you improve power output via intervals and if you become efficient at your chosen race distance, you will go faster. I think he is spot on.

Now the question of lactate threshold and HR is simply at what HR (for a given activity) does OBL (onset blood lactate) occur? In untrained individuals it happens immediately. Slow aerobic training helps a little, hard intervals (with a high lactate level) helps push this out a bunch. Ideally one would have OBL occur at maximum HR. Some top tier athletes have it occur in the 85-90% HR range. This is a crushing level of work output. Check out this paper from velo news.
It is excellent and completely ignored by most endurance athletes. Lactate threshold training is BRUTAL. Strength training is foreign to most endurance athletes. If it’s approached at all it’s in an inefficient and unhelpful way…typically bodybuilding. The answer then becomes more and more volume. Bad move.

Now as to the 4th question I honestly think the use of HR monitors is severely over hyped. The only thing that matters is : Can you generate more power in an absolute sense and what is your ability to sustain this output over time. This is the point from the Velo paper and the Power Running site. If you are able to track wattage (power output) you will get a sense of your ability to generate peak power output in short duration sprints and over longer distances. When you are able to generate more power for a longer period of time, your performance has improved. CrossFit has some slick technology for tracking this in a general sense by looking at total work performed in a given period of time and trying to increase that work output. You can use this nifty Work and Power Output Calculator from the Performance Menu to track mixed modal efforts.

Now health has an inflection point with regards to performance! The demands of truly elite level performance at most activities is typically at odds with health as measured by endocrine status, immune function and antioxidant levels. That said one can have VERY good health and performance if one approaches things intelligently! Let me know if all this makes sense.

One thing I’d add to this after thinking about it more is if we are looking at this problem from the perspective of an internal combustion engine the carburetor (oxygen) is not the limiting factor. The fuel, in this case glycogen and the consequent left overs of hydrogen ions (acid) lactate and other goodies are the limiting elements. We need buffering systems, transport molecules and a profound willingness to suffer if we want to push this ability to drive at high power output for a long time. The long slow efforts will not bring you to these results. Slow efforts obviously have a place in training but I think it is different than what most people need given their performance desires.The key to all this is increasing mitochondrial density, buffering systems, strength and mental toughness.

Think about it this way also: On Olympic weightlifter rarely if ever subjects his or her muscles to lactate. Consequently these folks have little capacity to endure lactate producing workouts. O-lifters have little mitochondrial density because their sport does not demand it. Similarly they do not have a developed buffering and transport system. Now in the case of an endurance athlete who only chuggs along at a plodding slow pace, these folks are never exposed to much lactate either. They do develop a bit more mitochondrial density…but ONLY in the slow twitch fibers they are using. This buys them a little if they are thrown into a tough anaerobic session but if they are called upon to recruit the large, powerful motor units they will crumble much the way the O-lifter would. The key here is if one wants a high degree of what passes for aerobic performance (run, bike swim-fast) one MUST have a highly developed anaerobic system that allows for maximum power production acutely and over time.

Robb Wolf

Robb Wolf, author of The Paleo Solution and Wired to Eat, is a former research biochemist and one of the world’s leading experts in Paleolithic nutrition. Wolf has transformed the lives of tens of thousands of people around the world via his top ranked iTunes podcast and wildly popular seminar series.