Having spent many years running far beyond a reasonable amount to attempt to improve health my blood count profile was that of a typical endurance athlete namely hematocrit and hemoglobin (H and H) at lower range of normal and a larger than average red blood cell size (measured as MCV).
What was going on was that I was running enough ( above some threshold value for a duration- intensity product) to have repeated exercise related episodes of intravascular hemolysis (break down of red blood cells (RBCs) in the blood stream.
Repeated hemolytic episodes cause increased RBC production to account for the loss of RBCs.Active endurance athletes have measurede RBC life span of around 74 days versus 115-120 in a more sedentary person. More production requires more iron for hemoglobin manufacture,
Normally the 1-2 milligram of iron loss daily ( largely through the GI tract as the short lived,iron absorbing duodenal lining cell slough off into the bowels) is easily replaced by iron absorption in some one with a normal western diet.
So that with adequate iron intake repeated episodes of hemolysis do not result in anemia.But perhaps not so in a person with meatless diet and even more so in a woman with poor diet who has the added menstrual related iron loss.
High school cross country coaches and runners are well aware of iron deficiency as a cause of poor performance and sports medicine doctors measure serum ferritin levels as a measure of iron status in their evaluation of an endurance athlete . The lay publication Runner's World has had well researched articles on runner's anemia for years yet in my experience general internists and even gastroenterologists seem unaware of the entity and somewhat shockingly even some hematologists. (note I have a very small sample size on which to base the preceding claim).
No comments:
Post a Comment