Iron deficiency struggle in athletes, be the winner!

April 6, 2020

Iron deficiency in athletes

Iron deficiency can attack different groups of people. If you have a healthy lifestyle, it does not necessarily mean that will not be at the risk of iron deficiency. Sure being healthy will lower the chances of it. But in some cases it may increase your risk of becoming iron deficient.

Iron deficiency affects women more than men. It is the same in athletes too. 24 to 47% of exercising women experience iron deficiency without anaemia. Endurance athletes are at more risk of low iron levels as well. A combination of different reasons leads to iron deficiency in athletes.

Causes of iron deficiency in athletes:

  • Inadequate amounts of iron in diet
  • Higher iron loss: Athletes are at more risk for blood loss. Blood is mainly lost through urine and sweat, often invisibly. Injuries cause blood loss too. Athletes who run on hard surfaces, or do extreme training, suffer from “foot strike” damage. Foot strikes, hitting the ground result in to red blood cells damage and iron loss. Menstruation enhances iron loss in female athletes as well.
  • Excessive use of non-steroidal anti-inflammatory drugs to ease the pains and inflammations.
  • After exercise, a hormone called hepcidin increases in the body due to inflammation. Hepcidin has an inhibitory role in iron absorption mechanism. As a result increase in hepcidin levels will cause depletion in iron absorption. Microencapsulated iron supplements like Irofix do not interact with this hormone’s function, therefore they are well absorbed.

Female athletes

To understand the true consequences of iron deficiency in female athletes, we need to be familiar with “female athlete triad”. Female athlete triad is a syndrome of three conditions: poor energy status, impaired bone health, compromised reproductive function.

  • Poor energy status: As a result of impaired thyroid function, increased risk of under eating and increased energy expenditure.
  • Compromised reproductive function: caused by impaired fertility and increased prolactin levels.
  • Impaired bone health: Due to impaired thyroid function, suppressed growth hormone and low blood oxygen.

Female athlete triad is a result of energy imbalance. Low energy status will lead to hypothalamus dysfunction, therefore causing menstrual irregularity and bone health issues.

Let’s discuss each arms of this triad and iron deficiency impact on them.

Poor energy levels

It has been seen in epidemiological observations that women with iron deficiency have a twofold greater risk for hypothyroidism. As such, exercising women may start to suffer from hypothyroidism signs and symptoms. Physical symptoms include cold sensitivity, hair loss, coarse skin, and constipation. Hypothyroidism also leads to low energy status, which is one of the arms of the triad.

Iron is an essential element in cortisol synthesis. As a result, being iron deficient leads to low cortisol levels. Cortisol is the hormone which controls your body’s response to stress by maintaining blood pressure, glucose levels and inflammation. Stress does not just mean psychological stress. Your body assumes hard exercise or going through a surgery as physical stress as well. Low cortisol levels will cause low glucose levels, resulting in poor energy status, enhanced muscle breakdown and diminished physical performance.

low iron levels causes resistance to growth hormone. hypothalamus releases growth hormone which is essential for high energy levels as well as muscle bulk and strength growth.

Restrictive eating disorders have higher rates in exercising women than inactive ones. Anxiety is one of the main reasons which can cause eating disorders. overall 90% of women anxiety proceeds to the diagnosis of eating disorders. We shall keep in mind that poor dietary habits are the lead cause of iron deficiency. It is no different in exercising women. Anxiety will cause diminished food intake. Therefor iron deficiency happens. Iron deficiency will lead to more anxiety levels. After that, this will keep going round in circles. in other words, iron deficiency cause low energy levels.

Compromised reproductive function

As mentioned before, chronic low energy leads to suppression of hypothalamus function and its related axes. One of these axes is responsible for the proper function of reproductive system. It maintains female sex hormones for a normal menstrual cycle. This leads to ovulation and fertility.

Compromised menstrual status secondary to low energy availability is called exercise-associated menstrual disturbances (EAMD). 56% of exercising women suffer from EMAD. Oestrogen is often decreased in most of the sufferers. In result Low oestrogen levels may lead to infertility. In addition low bone density and impaired blood lipid profile may happen.

It has been seen that iron deficiency compromises chances of getting pregnant. The reason for this condition may be due to the essential role of iron in cellular levels of ovum development.

Prolactin is a hormone which is mainly known for its role in producing milk in mothers after the baby’s first suck on the breast. But its functions are not limited to that. In its many functions, prolactin regulates oestrogen levels. Low iron levels lead to increased prolactin secretions, which results into oestrogen deficiency, thereby causing infertility.

Menstruation is a well-known underlying cause of iron deficiency. The longer the bleeding period, the higher the chance of iron deficiency. In reverse EMAD lowers the risk of iron deficiency in athlete women as it decreases the rate of blood and iron loss by menstruation.

Impaired bone health

Both low energy status and compromised reproduction can result in low bone mineral density. this happens via diminishing enzymatic and molecular pathways. Exercising women with amenorrhea (lack of menstrual periods) are at higher risk for fractures.

Increased bone re-absorption and decreased bone formation are results of iron deficiency. Both of these result in osteoporosis. low iron may suppress growth hormone, and growth factor further in some exercising women. This will contribute to poor bone health.

One of the iron deficiency side effects is low haemoglobin level. therefor low oxygen level happens. This is regardless of it causing anaemia. Prolonged hypoxia leads to bone absorption and reduction in bone formation.

As mentioned before, low oestrogen levels and hypothyroidism are two of the factors responsible for lower bone mineral density in active women. Iron deficiency triggers both of these conditions.

Men athletes

There is a misconception that male athletes won’t suffer from iron deficiency. But the latest researches indicate that the prevalence of low iron in this group is higher than what was thought before.

One if the risk factors of getting iron deficient is the kind of exercise as it may increase iron losses and inhibit iron absorption. Another risk factor is the age. Adolescent male athletes between the ages of 16 and 19 are the ones at most risk  among other age groups.

In conclusion, considering the great effects of exercising on the body and overall health, it is essential for each group of age to fit some activity in their daily routine. In order to get the most out of the work out, one should consider a healthy iron rich diet. Routine checkups to make sure your health is at its best are also essential if you are an endurance athlete. Then try to add an iron supplement to your daily diet. The best iron supplement is the one which does not taint your teeth, does not cause gut irritation and is well absorbed, even in time of inflammation.

References:

  1. Malczewska-Lenczowska, Jadwiga & Stupnicki, Rom & Szczepańska, Beata. (2009). Prevalence of iron deficiency in male elite athletes. Biomedical Human Kinetics. 1. 36-41. 10.2478/v10101-009-0010-1.
  2. Petkus, Dylan L., Murray-Kolb, Laura E., De Souza, Mary Jane. The Unexplored Crossroads of the Female Athlete Triad and Iron Deficiency: A Narrative Review. Sports Medicine March, 2017. 10.1007/s40279-017-0706-2
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