rekrunner wrote:
Armstronglivs wrote:
When I asked how does EPO "work" that means how does it affect an athlete biologically. Explain the processes involved. Secondly, how is it performance enhancing (which is why it is banned). What does it do that isn't naturally achievable. As one who is informed about the science involved these should be simple questions for you to answer. I am also interested in the scientific consensus on these questions, not outlier opinion. Oh - and don't forget the appropriate citations.
Before addressing your new questions, I'll take a moment to point out that you are conflating the application of the "scientific method" (my claim) with some alternate notion of "guided by science" (your claim).
The nature of my questions was not to get you to explain performance to me, as some sort of educational tutorial, but to get you to explain why you believe the things you say, or perhaps more importantly to me, why should I be persuaded by anything you say?
I could be snippy and tell you to get off your lazy backside and go back to the library and do your own research, but I believe I am bigger than that.
For perspective:
About 15 years ago, I took a heightened interest into the inner workings of the cell and the different processes used to produce energy from creatine phosphate, anaerobic breakdown of carbs, subsequent accumulation of lactate, aerobic breakdown of carbs and lactate, and aerobic breakdown of fat, with all kinds of names, like Krebs cycle, and diagrams, etc. After about 2 years of that, I realized that aerobics was only one small part of the big picture, and I decided that I was more interested in an overall performance model and real world performance results, which were influenced by many other factors: non-aerobic factors that improve economy and efficiency, and external factors like pacing, and drafting, and nutrition, and body weight, and the factors that can limit performance, such as heat accumulation, over-training, fatigued lower back muscles resulting in unstable hips and breakdown of form, fuel depletion (in marathons and ultras), low iron levels, etc. and various ways to prevent that, such as phased training with adequate recovery, cross-training, proper clothing, and in-race hydration and nutrition, including timing of nutrition, and iron supplementation, and other "legal" supplementation.
Now to address in part your questions:
Biologically, the production of EPO, or introduction of exogenous EPO, stimulates the production of red-blood cells. The exact biological processes don't interest me, because there is enough evidence that hematocrit increases, and Hgb levels increase. More red blood cells can improve delivery of oxygen from the lungs to the muscles, and carrying away CO2 from the muscles, back to the lungs. The exact biological processes here don't interest me either, as there is enough evidence that VO2max and sub-maximal VO2 improves measurably in the short term, with the blood changes, and correct training. Too many red blood cells can thicken the blood, like syrup, reducing blood flow to the muscles, undermining, or even reversing, this benefit, as evidenced by thrombosis. This is one part of "optimization", and in order to see any improvement, we must first be sub-optimal, which is more likely the case with random study subjects in various states of fitness, than with elite athletes.
"Secondly, how is it performance enhancing (which is why it is banned)?"
Some loaded assumptions here. First we must answer, is it performance enhancing, and if so, when is it performance enhancing, and for whom, in which events? Second, is it banned because it is performance enhancing? As I pointed out to you at the beginning of the thread, and in many other threads, WADA bans substances by committee consensus, based on (any 2 of) a potential to enhance performance (and/or potential to harm health and/or violating spirit of the sport), considering not just distance running, but a broad spectrum of all Olympic sports, and some non-Olympic sports.
The most studied benefit of EPO is how it enhances aerobic systems. If the athlete has a relative weakness "aerobically", and this is limiting his performance, than strengthening the aerobic component can improve overall "system optimization" in the short term, resulting in improved overall performance.
Another well studied benefit is placebo effect. Just deciding that you are taking a drug widely believed to enhance endurance performance can remove mental barriers that were limiting your performance, unleashing a potential that was always there.
I'm unaware of the research behind the other proposed benefits, such as protective, cognitive, and regenerative, but these don't seem to be of much concern to scientists.
"What does it do that is not naturally achievable?"
Another loaded assumption. I don't know if it does anything that is not naturally achievable. High altitude can stimulate EPO production naturally. If you go high enough, you can thicken the blood and get altitude sickness.
Some direction for further reading: an introduction to Exercise Physiology and an Endurance Performance Model:
http://www.owascoveloclub.com/Education_files/EXERCISE%20PHYSIOLOGY.pdfIf you want to boost your RBCs, I encourage everyone to do it legally. Here is a citation that may convince you:
https://journals.physiology.org/doi/full/10.1152/jappl.1997.83.1.102