- Aug 13, 2009
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Race Radio said:http://siab.org.au/what-is-blood-passport/passport-explanation.php
From the website of his research group. A decent overview
BikeCentric said:+1 on the vote for sticky. Make it so!
Cobblestones said:We should make that sticky.
Even better, we should create a quiz based on that piece and only people with a passing score should be able to post in relevant threads.
Excellent point. I already had gathered a library of links with documents that I have ready when I am having a discussion with somebody. here are some of them that I have used lately:BroDeal said:We should have a sticky "information" thread that only includes links to valuable information sources, enough that they form a foundation upon which most other discussions can be built. When noobs show up, we can point them to the info thread instead of digging up the same evidence/articles/whatever for the fiftieth time. The thread would have to be normally be locked to prevent extraneous posts.
I Watch Cycling In July said:I've been wondering about measurement errors and statistical significance for data interpretation too. Heres's a summary of the patchy info I have been able to glean from the net – if anyone has better info or corrections to add, that would be great.
A within-subject coefficient of variation for reticulocyte count of 11% is reported in this abstract http://cat.inist.fr/?aModele=afficheN&cpsidt=2295125. This study also reported that the change in reticulocyte count required to make one result significantly different from the previous result was about 35%. Reticulocytes are the most sensitive blood parameter to bone marrow stimulation, but the within-individual variability is higher than for hemoglobin and hematocrit (https://www.researchgate.net/publication/5573106_Reticulocytes_in_sports_medicine). This abstract also suggests that the variability in athletes is similar to the general population, and that reticulocyte count shows some modifications after training and during the competition season.
For hemoglobin concentration (Hb), http://cat.inist.fr/?aModele=afficheN&cpsidt=18672594 indicates that the better data analyzers have a SD of <0.25 g/dl. If we assume that UCI accredited labs have properly calibrated and high standard equipment, an error of 0.5g/dl seems like a reasonable estimate. It is worth noting though, that tourniquet time, blood drawing technique, body posture and storage can also affect results (http://www.ncbi.nlm.nih.gov/pubmed/18812283 and http://www.fims.org/files/311417173...08/Strategies-to-combat-doping-in-cycling.pdf)
Natural variation in Hb depends on changes in blood volume, mostly due to dehydration/plasma shift, and changes in the total hemoglobin mass (Hbmass). Natural variability in Hbmass seems to be quite small (within 2%) for normal healthy adults (http://jap.physiology.org/cgi/content/abstract/104/4/982), although changes of around 5% have been observed with altitude (e.g. http://jap.physiology.org/cgi/content/full/100/6/1938 and http://www.ingentaconnect.com/content/mksg/sms/2008/00000018/A00101s1/art00008). Conversely, some studies have found little or no altitude affects on Hbmass but this might be because the altitude wasn't high enough, or the training wasn't right (http://www.ncbi.nlm.nih.gov/pubmed/18768367.) Endurance training might also cause a small increase in Hbmass (http://www.wada-ama.org/rtecontent/document/SCHMIDT.pdf ) and chronic fatigue/illness/injury can presumably lead to a decrease.
Plasma volume changes can have a substantial effect on Hb. For example, an approximately 7% decrease in Hb and hematocrit, for 7 elite cyclist during a GT, has been attributed to plasma volume expansion (http://cat.inist.fr/?aModele=afficheN&cpsidt=20274125). Elapid posted more interesting info on plasma volume changes here http://forum.cyclingnews.com/showthread.php?p=83969&highlight=plasma#post83969. Further information on Hb variability in general can be found here http://www.mendeley.com/c/92011807/Mørkeberg-2009-Changes-in-blood-values-in-elite-cyclist/. Another example is plasma volume response to altitude. This usually begins with hemoconcentration in the first few days, which reverses to a more gradual plasma expansion, but the between-subject variability after a few weeks seems very high e.g. http://jap.physiology.org/content/vol100/issue6/images/large/zdg0060666600002.jpeg.
Please note that many of these points are from abstracts or non-peer reviewed articles, and hence may have limited application for data interpretation.
Finally has there been a good discussion on local cyclist part 4 somewhere that I missed?