Why laborathory test sucks....

Befor I put my critiques on lab test I must say that there is time and place for everything and also for lab tests. They can be used for rehab, recreaction and can be helpfull in control of training proces but NOT for selection, decision making, evaluation etc…

First of all if we look at the human with help of system theory, we have inputs, outputs and internal states of the system (generaly speaking). Internal structure of human and its internal function is very complex and we cannot conclude about the system output arguing about its complex internal states (confusing? dont matter it is not crucial for discusion).

Why indirect calorimetry sucks
Measuring work done with indirect calorimetry is based on O2 consuption, CO2 removal, RER (RQ, respiratory ratio CO2/O2). Based on O2 and RQ you calculate energy usage. Why this sucks?

  1. RQ table is not precise because Protein metabolism and glyconeogenesis processes in liver are not included
  2. When RQ is over 1 it unusable (crossing OBLA)(most common in sports)
  3. CO2 removal from the lungs is not same as in tissues, especial after accumulating acid metabolic products. Also it is not the same during non-stabile-states (most common in sports)
  4. A lot more wich I cannot think of it now :slight_smile:

On my own opinin VO2 sucks and it is unusable because it is like measuring gas consuption in a car and trying to calculate the car speed. This depends in wich gear are you, what is the type and power of engne, mass of vehicle, wind resistance, steepnes of a hill and many more. So you cannot measure some process in the system and make a decision about the output. Output here is athlete performance. So I think it is better to introduce qualitative subjective analysis of athelete performance. Look at him, hear the sounds of his feet, see the color of his skin, sweat, look at the face, quality of movements etc…

Why blood lactate test sucks
First of all LA is not the cause of muscle fatigue. Its H+ ions. LA and H are the products of lactid acid wich is a reduction of pyruvic acid (result of glycolitic proces).
Level of bLA is dtermined by its production in muscles, its transfer to a blood and its removal from the blood. So measurng bLA suck because:

  1. You dont know is there a dominance of production, crossing or removal of LA
  2. You dont know how much of LA and H+ is in muscles
  3. Muscle have a lot of fibers, so they have different concentration of LA an H+ and have different impact on performance
  4. there is time lag between production and measurement in the blood (time to ente circulation)
  5. It is impractical

So again my conclusion is that based on the bLA and VO2 you cannot make predictions what is happening exactly in the system. It is better to look at it as a black box and making a predicions based on the input/output relations.
Look at the performance, not the test result chart!

I can see your points there; just a couple of things from what I’ve seen:

  1. prediction of endurance performance (e.g., running) is possible, and
  2. such tests and mainly a Bla test is useful for monitoring an endurance athlete under normal/standardised conditions.
    I am not trying to dispute anything you are saying here, but rather to add, if you want.

How could I forget measuring HR??? :slight_smile:
Why it sucks?

  1. It depends on VO2 consuption wich is non-usable data for descibing system behaviour and ouput
  2. It depends on sympaticus/parasympaticus activity and hormonal status
  3. It depends on body teperature
  4. It depends on emotional and arousal status of athlete
  5. It depends on wheater condition
  6. It depends on the inertial characteristics of cardio-vasc system and its the response of their control center (medulla and hypotalamus)

Along with this cons it can be usable in training but watch out… making decision too early or based on wrong data is more dangerous that not making them…

Hi nik, where are you man? :slight_smile:

  1. It is posible to predict performance, but they srongly depend on the efficiency of running (VO2-runing speed). On the other hand in medium distance it is also important to introduce LA tolerance, and psychological motivation etc…
  2. normal/standardised conditions do not exist so there is always error. What if athlete produces the same lactic acid but same La enetrs blood and more H+ stays in muscle? It will be more acid and fatigued (performance drops) but the bLA test will be the same.
    On the other hand what if is the circulation in ears totaly droped (due the blood redistribution)???
    I know that you are not going to dispute this because you make me think this way dude :wink:

I agree on your first point; however, if you know the athlete pretty well, you can predict performance with some accuracy -e.g., r=0.81 from personal data and even more precisely from others’ data (for example: http://www.charliefrancis.com/community/showthread.php?p=101133#post101133)

By normal/standardised conditions I meant those that can be maintained and be repeated in a lab setting, which can be done to a much greater extent vs. outdoors.
When you take a blood sample, you are not examining lactate kinetics, you are just getting an indication of his/her state. For lactate kinetics observations, for example, you need to use isotopes, which I haven’t been lucky enough to be invloved in; it’s very interesting though -George Brooks, if you are in this field, or interested.
Also, it’s good to keep in mind that if the same Bla curve is produced, but with reduced performance, overtraining might be another possibility that needs to be examined -and this is on endurance runners, not sprinters.
If ear samples are difficult, use a finger; if both are difficult, leave it! :slight_smile:
See, I am just chating here! :wink: