Iron Loss Through Sweat: What Athletes Need to Know

Foot strike, which is a calculation of how and where the foot makes contact with the ground, is a common concern among athletes.

Runners, in particular, regularly lose iron through their feet due to a phenomenon known as foot strike hemolysis. However, this isn’t the only iron-related concern that runners have.

Here is a discussion about how iron can be lost through sweating and what can be done to restore healthy iron levels in an athlete’s body.

How Is Iron Lost by Sweating?

The body loses iron in a variety of ways, including through blood, urine, and sweat. Iron deficiencies can occur in practically anyone; however, athletes are at a higher risk than the general population. Athletes can also be at a higher risk of iron loss if they have gastrointestinal bleeding, foot strike hemolysis, or habitually use anti-inflammatory drugs.

How Much Iron Is Lost Through Sweat?

For most athletes, the amount of iron lost through sweat is negligible and doesn’t impact overall performance. However, the amount of iron lost can increase in hot and humid conditions. Over time, those small iron losses can add up and result in a more serious condition.

According to a study published in the American Journal of Clinical Nutrition, iron loss is directly related to the volume of sweat lost and has been calculated at 22.5 micrograms iron per liter of sweat. Another calculation suggests that one may lose about 1.2 milligrams of iron with each gallon of sweat, making up a loss of about 0.3 milligrams of iron per liter of sweat. This amount of loss could have an impact on the amount of iron consumed daily.

Sweat Iron Concentration

A study involving male and female athletes exercising in a hot environment tested the amount of sweat collected on the arm and iron lost. The researchers found that the sweat iron concentration was greater in hot environments while exercising and neutral environments compared to hot environments while not exercising. Sweat iron concentration also seemed to decrease during exercise.

Who Is at Risk of Iron Loss Through Sweat?

Athletes who are prone to heavy sweating and who work out in hot conditions are generally more susceptible for greater iron loss. Male athletes are also more prone to heavy sweating, and therefore greater losses of iron through sweat, when compared to their female counterparts.

How to Treat Iron Deficiencies in Athletes

There are many different treatment approaches to address iron deficiencies in athletes. But one of the most common methods is to take iron supplements like Fergon. Sweating alone will rarely cause an iron deficiency in athletes. However, if excessive sweating is paired with other risk factors or poor nutrition, the symptoms of iron deficiency could begin to occur and impact athletic performance and overall wellness.

Athletes should also know that sweating can result in nutrient and mineral losses of other types as well. For example, calcium, magnesium, manganese, potassium, sodium, and zinc levels should also be monitored in athletes who sweat excessively as part of a regular exercise routine.