at 50 in terms of red blood cells? Anyone know?
Not the general population, but in world class athletes, it is probably around 5% as a guess… People with genitic gifts physically will tend to excel in sports, and those at the top will often have the most genetic gifts…The general population of Tibet proabaly has a 80% rate…
When I googled, my first hit was an article on Tibetan chickens (http://ps.fass.org/cgi/content/abstract/86/7/1384)… I bet they can climb.
Ah, but here’s an article that is interesting
http://content.nejm.org/cgi/content/full/333/19/1248?ck=nck
Tibetan infants were born with lower hematocrit than that of infants from another group, whose families moved to the Himalayan plateau much more recently.
Arterial Oxygen Saturation in Tibetan and Han Infants Born in Lhasa, Tibet
- Susan Niermeyer, M.D., Ping Yang, M.D., Shanmina, M.D., Drolkar, M.D., Jianguo Zhuang, M.D., and Lorna G. Moore, Ph.D. *
ABSTRACT
Background Reduced oxygen availability at high altitude is associated with increased neonatal and infant mortality. We hypothesized that native Tibetan infants, whose ancestors have inhabited the Himalayan Plateau for approximately 25,000 years, are better able to maintain adequate oxygenation at high altitude than Han infants, whose ancestors moved to Tibet from lowland areas of China after the Chinese military entered Tibet in 1951.
Methods We compared arterial oxygen saturation, signs of hypoxemia, and other indexes of neonatal well-being at birth and during the first four months of life in 15 Tibetan infants and 15 Han infants at 3658 m above sea level in Lhasa, Tibet. The Han mothers had migrated from lowland China about two years previously. A pulse oximeter was placed on each infant’s foot to provide measurements of arterial oxygen saturation distal to the ductus arteriosus.
Results The two groups had similar gestational ages (about 38.9 weeks) and Apgar scores. The Han infants had lower birth weights (mean , 2773±92 g) than the Tibetan infants (3067±107 g), higher concentrations of cord-blood hemoglobin (18.6±0.8 g per deciliter, vs. 16.7±0.4 in the Tibetans), and higher hematocrit values (58.5±2.4 percent, vs. 51.4±1.2 percent in the Tibetans). In both groups, arterial oxygen saturation was highest in the first two days after birth and was lower when the infants were asleep than when they were awake. Oxygen saturation values were lower in the Han than in the Tibetan infants at all times and under all conditions during all activities. The values declined in the Han infants from 92±3 percent while they were awake and 90±5 percent during quiet sleep at birth to 85±4 percent while awake and 76±5 percent during quiet sleep at four months of age. In the Tibetan infants, oxygen saturation values averaged 94±2 percent while they were awake and 94±3 percent during quiet sleep at birth and 88±2 percent while awake and 86±5 percent during quiet sleep at four months. Han infants had clinical signs of hypoxemia — such as cyanosis during sleep and while feeding — more frequently than Tibetans. Conclusions In Lhasa, Tibet, we found that Tibetan newborns had higher arterial oxygen saturation at birth and during the first four months of life than Han newborns. Genetic adaptations may permit adequate oxygenation and confer resistance to the syndrome of pulmonary hypertension and right-heart failure (subacute infantile mountain sickness).
Wow, it looks like the Tibetan kids are so adapted in other areas, that the need for high Hematocrit has been bred out of them. The later babies still have the genes turned on for survival, so they test higher. Makes sense if you look at it historically…I wonder how much they retain as adults, I know you are at your highest % naturally when you are young…When I see those sherpas climbing with all that weight at 28,000ft., I just amazed at their endurance in such thin air…
Here’s another:
http://www.springerlink.com/content/l3152674v34563h4/
I don’t know if you can read the full PDF, but they have a table of age / gender / altitude broken down into Han and Tibetan groups.
Don’t know about the general population, but over the past 4 or 5 years, mine has tested between 48.2 and 48.8 at my annual physicals, and I’m in reasonably good shape for someone my age, but don’t treaten for podium spots even on a local tri AG level. If your levels are higher when you are young, then mine may have been 50 or higher 20 plus years ago when I was a reasonably competent (but not really that fast) a swimmer. Probably one of the reasons I am, relatively speaking, much better the longer the race goes.
WOW!! 41 - 60 yr old Han males are off the chart, 60+%!!! That means the average for all of them at all the altitudes, puts them all way over 50%…You can see why they had to change the rule on that one, he is an entire population that would still get sent home , if they were to race… I bet the Columbians are not too far off either, wonder about Solar’s… Great climbers that live at altitude really have a tendancy to have high ones…
thanks all for the research! Why were your levels tested during a physical, per your request? If I ahve been tested I dont know about it.
I think its included in a basic blood work up, at least it has been in the ones I’ve had. What surprised me is the the bottom of the normal range is in the mid 30’s.
It’s just part of the normal blood work that my doctor requests. I didn’t even know that he was testing for it until last year when he mentioned what it was. I was kind of surprised at how high it was given that they throw people out of various races for being 50 or higher.
There’s a custodian at work, 71 years old (looks not a day over 55), who rides all the time- he still puts in well over 100 MPW. If I remember correctly, he’s originally from Peru, ethnically from a group called Ketuan (spelling likely way off). Anyhow, these folks live at similar altitude as the Tibetans; he says that all are built like him- wiry muscles, gigantic rib cage to hold large lungs (5’5" and a vital capacity of over 5 L). I wonder how a team of these guys, trained as endurance athletes, could perform?
A little off topic…but there is a guy in Muncie who rides his bike Every-Day-Of-The-Year. He rides around on a 50 lb. beach cruiser. He usually is wearing Jeans, but he rides 100+ mile rides with his Walkman on regular basis…he has been pulled over while heading on the on ramp to I-70…He can hold 21-22 mph for a long time and will ride with you until the road goes uphill…I wonder what kind of numbers he would put up if tested in a lab
Well I made the comment about how few 50% hct’s I see. I see the hematocrits of women and didn’t realize how much lower they are then the crits of men ( about 4%) Apparently in men the answer is 2.8-3.4% naturally run over 50. Here’s an article from 97 that argues that the level UCI uses should be @ 52. Truth is that with altitude I think a man probably can run around 50 legally pretty easily. Of course, that begs the question of why there seems to be EPO use and blood transfusions.
http://sportsci.org/news/news9703/AISblood.html
P
Not the general population, but in world class athletes, it is probably around 5% as a guess… People with genitic gifts physically will tend to excel in sports, and those at the top will often have the most genetic gifts…The general population of Tibet proabaly has a 80% rate…
your guess regarding athletes… here’s reality- Tour de France riders- their hematacrit was in the 38 to 40 range - PRE EPO drugs in the mid to late 1980s…
also- Tour de France riders- specifically, have their RBCs drop during the race- b/c of the intense exercise- red blood cells die, do not replicate fast enough to replace dead RBCs, so their hematcrit drops as the tour progresses
early 1990s- post EPO- their hematacrit was lower 50s to 60, then hematacrit test came in the later 90s and cyclists are near 50… artificially of course!
your guess regarding athletes… here’s reality- Tour de France riders- their hematacrit was in the 38 to 40 range - PRE EPO drugs in the mid to late 1980s…
also- Tour de France riders- specifically, have their RBCs drop during the race- b/c of the intense exercise- red blood cells die, do not replicate fast enough to replace dead RBCs, so their hematcrit drops as the tour progresses \
I can’t argue with that. We all have lower %'s when we race, or train hard. Of course I believe that most of the peleton was using EPO when it came out. THere were riders dying of strokes and heart attacks all over the place because their blood got so think. I heard stories of 60 - 65% before there was a limit. I also agree that riders with low natural %'s will dope to bring it up to code so to speak. I agree with all of what you said…
But that doesn’t mean that a small % don’t have naturally high numbers, over 50%… I personally know of a few, we have heard from a few more here on this thread, and there is evidence that an entire population has a normal average over 50%. So do you think my 5% guess is out of wack, or do you think it should be larger???
I measured at 50.0% once. Other times have been around 44-46%. I have all of it saved just in case.
I was not doing anything special aside form lots and lots of swimming.
your guess regarding athletes… here’s reality- Tour de France riders- their hematacrit was in the 38 to 40 range - PRE EPO drugs in the mid to late 1980s…
also- Tour de France riders- specifically, have their RBCs drop during the race- b/c of the intense exercise- red blood cells die, do not replicate fast enough to replace dead RBCs, so their hematcrit drops as the tour progresses \
I can’t argue with that. We all have lower %'s when we race, or train hard. Of course I believe that most of the peleton was using EPO when it came out. THere were riders dying of strokes and heart attacks all over the place because their blood got so think. I heard stories of 60 - 65% before there was a limit. I also agree that riders with low natural %'s will dope to bring it up to code so to speak. I agree with all of what you said…
But that doesn’t mean that a small % don’t have naturally high numbers, over 50%… I personally know of a few, we have heard from a few more here on this thread, and there is evidence that an entire population has a normal average over 50%. So do you think my 5% guess is out of wack, or do you think it should be larger???
some riders do have hct (hematacrits) above 50%… more likely in the off season when their body is more at rest- they can have a doctor monitor their blood for a period of time and get an ‘exemption’ to the 50% limit (it’s actually 51% for testing error reasons) and the exemption will allow them to have a higher limit- Jonathan Vaughters was one such cyclist with this exemption… he was naturally around 50/51…
All I know is the numbers from Tour riders (the best of the best in the 1980s… no reason why today’s athletes are better- from a hct perspective (assuming they were drug free).
also- the limit for female riders is 48%, males is 50%…
I’m a lowly 41.5%! My wife is 42.5%… (too bad we are too normal!)