Exercise and Low Iron Levels

What is iron and why do we need it?

Iron is a crucial dietary mineral that the body needs to combine proteins that are responsible for transporting oxygen around the body, and to create enzymes necessary to produce energy. As a consequence of low iron levels, feelings of fatigue, lethargy and poor concentration are usually present. 

What causes low iron levels?

The body is unable to form its own iron when imperative, therefore, dietary intake of iron is required to counteract daily losses to maintain a healthy iron balance. 

Restoring the body’s iron levels can be difficult as the body only absorbs 2-35% of the iron that we get through our diet. It is recommended that males consume 8mg of iron per day and pre-menopausal adult women consume 18mg of iron per day to account for menstruation.

If we don’t meet our iron needs, the body will begin to use out iron stores which will then become depleted resulting in an iron deficiency.

Who is at risk of an iron deficiency?

Females and those who follow restricted diet patterns (e.g. vegans and vegetarians) are at a much higher risk of developing an iron deficiency. This is because extra iron is lost during menstruation and greater daily iron consumption is necessary to balance out these losses. 

Also, if not managed sufficiently, restricted diets (vegan and vegetarian diet) may lead to reduced energy intake and micronutrients including iron. Haem iron is acquired from animal based food and is absorbed in the body substantially better than non-haem iron which is found in plant based food. 

How can exercise impact iron levels?

Iron and its role in oxygen transport and energy metabolism is crucial to our exercise capacity. There are many exercise induced methods of iron loss including sweating, gastrointestinal bleeding and the demolition of red blood cells via weight beating activity. This supports why dedicated exercisers are vulnerable to iron deficiency. 

Studies have shown that there is an association between exercise and the body’s main iron absorption regulator, hepcidin. This hormone is produced by the liver and functions to decrease the consumption of dietary iron and decrease the body’s ability for iron recycling. It has been found that there is an increase in hepcidin levels 3 hours after completing exercise, showing that there is a period of time post-exercise with decreased iron absorption. 

Tips for improving iron levels

Timing is key. Studies have shown that hepcidin, the iron regulatory hormone, is lower in the morning which suggests that the absorption of iron will be greater in the morning. 

Research has also looked into the timing of exercise and iron absorption. The most significant absorption of iron was seen when a high dose of iron was ingested within 30 minutes of finishing exercise. 

References

Right, E. (2022, April 26). What you need to know about exercise and low iron levels. Exercise Right. https://exerciseright.com.au/what-you-need-to-know-about-exercise-and-low-iron-levels/