Jewish World Review April 22, 2003 / 20 Nisan, 5763

Anemia: for athletes, it could be the real thing or a "pseudo''condition

By Marlene Cimons | Anemia can be confusing. Most people think it has to do with not having enough iron in your blood. But it can be more complicated than that.

To be sure, iron deficiency is a major cause of anemia. But insufficient iron is not how anemia is strictly defined. Anemia actually results from losing too many red blood cells -- the cells that contain hemoglobin, the pigment that carries oxygen to the body from the lungs. Anemia occurs when there is not enough circulating hemoglobin.

The blood's reduced ability to carry oxygen results in many familiar symptoms (it's not surprising that "tired blood'' has become shorthand for anemia): pallor, weakness, dizziness, fatigue, shortness of breath and sometimes heart abnormalities.

About 3.4 million Americans have anemia; of them, 2.1 million cases occur in people younger than 45. Women suffer far more frequently than men, and it is one of the most common medical conditions among athletes.

People with anemia usually have low hemoglobin, a low red blood cell count and a low hematocrit, too. The latter test measures the ratio of red blood cells to the total blood, and can lead to considerable confusion, too.

There are two anemia conditions related to sports -- one real, the other false.

Strenuous exercise can produce "foot strike anemia,'' a true anemia that is an actual reduction in red blood cells. Exercise can also produce a false anemia, known as "pseudo'' anemia, which occurs when the red blood count wrongly appears to be depleted. This creates a situation for athletes that actually may turn out to be beneficial, although it doesn't seem so at first.


Athletes who train tend to increase their plasma volume (plasma is the liquid part of the blood, which makes up about half its volume; cells make up the other half) so the percent of red blood cells often goes down as the plasma volume goes up.

This can be deceptive because the number of red blood cells has not actually dropped -- only its proportion to the plasma volume. So it may falsely appear in a hematocrit reading that the red count has gone down, raising concerns about anemia.

"There is the tendency to look at these values, and say `whoops, this looks like incipient anemia,' when it isn't,'' says Russell Pate, the associate dean for research at the school of public health at the University of South Carolina. "It does not mean in a clinical sense that a person is anemic. It means the blood cell volume hasn't increased as much as the plasma volume.''

In pseudo anemia, your oxygen-carrying capacity is unaffected, says Charles Peterson, M.D., program director of the blood diseases program at the National Heart, Lung and Blood Institute, part of the federal government's National Institutes of Health in Bethesda, Md.

"It's a concentration issue, like putting more water in a bucket and diluting what's in there,'' says Frank Pizza, an associate professor in the department of kinesiology at the University of Toledo in Ohio. Increasing the plasma volume through running is going to dilute the constituents of the blood, he adds, which is a good thing. "If you have more concentrated blood, it's more viscous -- and the more viscous it is, the harder it is for the heart to pump.''

If you were tested in a physician's office, it would look as though the hemoglobin was low, but you'd need to run much more specific tests, he says.


Every time your foot hits the ground, red blood cells can be destroyed, depleting cells and iron. Experts believe most runners shouldn't be too concerned unless their mileage is high and their iron levels are borderline to begin with.

Foot strike anemia is just what it sounds like, says Dr. Plate. "When blood circulates in your feet and you land on them, you squish red blood cells. Red cells have a limited life span, and they constantly break down. Running probably kills off some of those blood cells a little earlier than average.''

Runners who experience an unexplained drop in performance or unusual fatigue should undergo "a full diagnostic panel, including the measurement of serum ferritin -- a tissue molecule that is used to store iron in the body tissues -- and iron binding molecules,'' says Dr. Plate.

The ratio between the two is an important marker, which enables you to distinguish between the dilutional pseudo anemia -- which is common in athletes -- and true anemia, which is indicated by lower-than-normal red cell volume.


It can be. Research conducted by Pizza published in the August 1997 International Journal of Sports Medicine showed runners and swimmers both experienced pseudo anemia during high levels of training, but that doctors saw no signs of true anemia.

However, at the end of the training season, researchers saw a modest reduction in iron stores, raising the possibility "that years and years of training could significantly reduce the body's iron stores,'' he says.

Iron can be lost in other ways -- through undetected internal bleeding, for example, or menstruation.

Diet also often plays a role. "If you're eating vegetables, spinach and some red meat, you'll do fine,'' Dr. Peterson says. "Vegans -- who eat no eggs, meat or milk products -- are the most vulnerable. Vegetarians are also at risk.''

Some medications -- aspirin and ibuprofen, among them -- can cause gastrointestinal bleeding resulting in anemia.

Anemia also can be genetic. Hereditary disorders can shorten the life span of red blood cells, leading to anemia (as in sickle cell anemia.) And other hereditary disorders can also cause anemia by impairing the production of hemoglobin.


When anemia is diagnosed, sometimes additional iron is all that is needed, either through diet or supplements.

Obviously, if the cause is more serious -- internal bleeding from a tumor, for example -- anemia becomes the symptom rather than the problem. And it becomes critical to diagnose and treat the underlying disease.

Most "fitness'' or recreational runners don't have much reason to worry about their running causing anemia, unless they are already iron-compromised, borderline anemic or have a history of anemia.

There are some steps you can take to reduce your risk.

-- Don't go overboard on your mileage. High mileage means more foot strikes. Avoid hills, especially downhill, where the pounding is more intense.

-- Watch your diet. Eat your vegetables. And "although this is something most runners don't want to hear, eat red meat -- the redder the better -- which has the most readily absorbable form of iron,'' Dr. Pate says. "Supplements help, but they don't replace a good diet.''

-- If you have a history of any problems with anemia, it makes sense to monitor your status through blood tests from time to time, Dr. Pate says. "How important this is depends a great deal on how much running you're doing and how competitive you are. The higher you get competitively, the more it becomes an issue.''

Comment by clicking here.


© 2003, Distributed by TMS