Correcting iron deficiencies in endurance athletes.

By Jeff Rocco, MD

Introduction

Iron is a critical mineral for performance in endurance athletes. The abridged story of iron is that it is necessary to create hemoglobin, which is the protein used by red blood cells to deliver oxygen and remove carbon dioxide from an athlete’s exercising muscles.  

More hemoglobin = More oxygen delivery + CO2 disposal

Previously we have presented and discussed some of the basics of iron metabolism.  For a review of that material please see the Iron and Endurance Athletes article.

What follows is a discussion of symptoms, causes, diagnosis, and treatment of iron deficiency anemia in endurance athletes, including how MultiV can be part of an iron repletion and maintenance regimen.

As it turns out, many endurance athletes are iron deficient. In fact, about 90% of the patients I have evaluated for iron deficiency tested positive, and it seems that the higher performing athletes are more severely affected.

Recently, I have also personally experienced the diagnosis of iron deficiency – and the subsequent benefits that occurred when the deficiency was corrected.

Symptoms

Symptoms of iron deficiency may be mistaken for over-training syndrome (OTS).  Previously, we have discussed OTS here: How To Stop Cortisol and Overtraining Syndrome From Wrecking Your Season. The athlete may simply feel generalized fatigue and find no improvement (or decreasing) performance despite vigilance and attention to recovery, nutrition, and training plans. Assuming that bleeding such as from a colonic polyp or heavy menstruation have been ruled out, the mechanism for anemia in endurance athletes is not entirely clear.

Causes

Foot strike hemolysis is occasionally cited as a possible culprit. It can occur in runners when repeated foot falls cause mechanical breakdown of red blood cells; however, recent studies have shown that this effect may be clinically insignificant., Foot strike hemolysis also fails to explain why cyclists exhibit iron deficiency anemia with alarming frequency.

More recently, oxidative stress and inflammation caused by high volume of exercise and high-intensity exercise have been proposed as the cause of alterations in the red blood cell membrane, subsequently resulting in hemolysis., That suggests the cause of athletic induced anemia may just be the increased levels of oxidative metabolism seen in endurance athletes compared to sedentary individuals.

Diagnosis

Iron deficiency anemia is diagnosed with blood tests. The tests necessary to make the diagnosis include a complete blood count (CBC) with differential, and an iron panel which includes: serum iron, total iron binding capacity (TIBC), iron saturation, and ferritin.

The range of normal is quite wide, and many times patients – and especially athletes – may be told their levels are normal, when in fact they are low. Here’s why: Normal values can vary between laboratories, and normal is a range of values clustered around a mean value for that particular lab. In other words there are a lot of results that are considered “normal” simply because they occur commonly.  Many of the population tested have some sort of illness that may cause a low hematocrit, so while the results for these patients might be considered normal for those specific circumstances, they are far from normal for a high-performance athlete.  

For example, consider hematocrit (the volume percentage of blood that is made up of red blood cells). The normal range for hematocrit is 40-49% for men and 35-46% for women. Doctors are used to treating patients with medical conditions that cause their patients to have hematocrits in the anemic range. So when a doctor sees a 45-year-old age group athlete who lives at 5000’ above sea level with a hematocrit of 39%, that athlete might be told their hematocrit – and therefore their iron level – is within the normal range. However, if the doctor digs a bit deeper and orders an iron panel, more information is uncovered. Let’s consider that same athlete with the following lab results:


Test

Value

Normal

Hemoglobin

13.2

13.3-16.7 g/dL

Hematocrit

39.7

40.0-49.6 %

Iron

68

65-175 mcg/dL

%Saturation

21.7

20-50%

TIBC

314

250-450 mcg/dL

Ferritin

153

5-244 ng/ml


A doctor might look at those results and conclude that this hematocrit and iron panel are both normal. But they aren’t. Not for an otherwise healthy athlete who lives at 5000’ above sea level.

Living and training at altitude should stimulate red blood cell production to the high end of the normal range, but the values for hemoglobin and hematocrit are at the low end of the range. An Iron level of 68 is much closer to 65 than it is 175.

Additionally, if this athlete had been female, this same lab might have reported the low end of the range as 37mcg. Iron levels shouldn’t be lower in women, but they commonly are due to menstruation and child bearing; a woman’s iron stores can drop by as much as 25% with every child she bears.

In light of this context, the low % saturation and the normal TIBC in the example above tell us that this athlete’s body has the capacity to deal more iron.

Correcting the deficit

Common sense might suggest this athlete must just need a better diet and some iron supplements. Come to find out that this athlete has already been on supplements for the past 3 years and is still low on iron.

The point here is that it takes years to improve total body iron stores with oral supplements, and may not even be possible at all.  The body has a difficult time absorbing enough iron to keep up with the depletion caused by high volumes of intense exercise, so intravenous (IV) therapy is ofetn required to make any real, meaningful change. After IV iron treatment, this particular athlete’s hematocrit increased from 39.7% to 45% in just 6 weeks. That’s a 13.3% improvement, which translates into 13.3% more oxygen carrying capacity.

To treat iron deficiency anemia I generally recommend a total of 5 IV infusions of iron with one week between each infusion. The week between infusions gives the body time to process the iron and bind it to proteins.  Too much iron, given too quickly, can be toxic and cause liver damage. The infusions generally are given slowly over about half an hour. During the 5 week period of the infusions, it is important for athletes to consume extra protein, up to 1g per pound of body weight. The body needs both iron and protein to manufacture the red blood cells.  Athletes can and should continue to train as usual during the infusion period. Many patients (athletes included) start to feel like they have more energy after only one or two treatments.

Maintenance with MultiV

Once IV therapy has been completed, additional IV therapy should not be needed for years. At that point iron levels can be maintained with an oral supplement. First Endurance MultiV has a good dose of iron (18mg of elemental iron, chelated) for maintenance purposes. In my own personal experience, this approach to iron deficiency has helped me to not only to perform better, but to feel better too.

December 29, 2022 — First Endurance

Comments

swim said:

heme -iron. Red meat &animal proteins/animal organs. Iron that has hemoglobin in it! And avoid the gastro of elemental chelated iron.

tony giguere said:

with your " normal" levels. how do you convince your doctor to give you an iron infusion? i have very similar iron levels but only when my ferritin is below normal will they consider the infusion. what type of iron infusion do you get? thanks for the info. tony

Warren C Mullisen said:

is there a specific iron only supplement you recommend?

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