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Simply Fit, by Cindy Haskin-Popp, will help you make physical activity a part of everyday life. The health benefits of regular exercise and overall daily physical activity will be discussed. Fun, practical and easy-to-follow tips on an exercise program will be shared, as will the most current research. Fitness tips for families and seniors, on fitness centers and on buying proper and affordable equipment will be regularly given. 

Monday, August 10, 2009

Iron-Deficiency Anemia and the Active Individual

Have you been feeling tired lately? Are you lacking the energy to tackle your daily activities? Or, have you noticed a recent inability to keep up with the others in your Zumba class? Some obvious causes of your fatigue could be an insufficient amount of sleep at night or maybe you are putting in extra hours at work. But, your fatigue could be the result of something more than that.

A trip to your physician for a complete evaluation may reveal that you are suffering from iron-deficiency anemia, a condition characterized by a reduced oxygen-carrying capacity of the blood. Iron deficiency is a common nutritional deficiency, especially among active females of childbearing age. Iron is needed by your body to form hemoglobin and myoglobin, essential oxygen-carrying proteins in the blood and muscles, respectively. It is also needed to make enzymes that play a role in energy production. If your body is using more iron than what it is taking in, red blood cell formation and hemoglobin production are impaired.

Low iron levels reduce the oxygen carrying capacity of your blood. If there is not enough oxygen transported to your muscles, fatigue sets in, reducing your endurance capacity during exercise and leading to a general feeling of tiredness throughout the day. Low iron levels can also effect the functioning of your brain, which relies on an adequate supply of oxygen, causing such symptoms as irritability, poor concentration, decreased attention span, and impaired learning. Other symptoms of iron deficiency include a sensitivity to cold, weakness, and impaired immune function.

Who is at Risk?
  • Females, particularly active/athletic women of childbearing age, due to iron loss through menstruation.
  • Pregnant women who need more iron due to the increased blood volume associated with pregnancy.
  • Active individuals/athletes, especially those engaging in endurance exercises. The need for iron in these individuals is increased by approximately 70%. Iron is lost through sweat, therefore heavy sweating could contribute to lower iron levels. Runners can also experience what is called "heel strike" hemolysis in which the red blood cells are damaged as the feet make contact with the ground, thus effecting iron status.
  • Children experiencing growth "spurts" which involve quick increases in blood volume and red blood cell formation.
  • Vegetarians/vegans because iron consumed from plant-based sources is not as readily absorbed by the body as it is from animal sources.
  • Those who consume a diet that is deficient in iron.
  • Regular blood donors
What is the Recommended Daily Intake?
  • Women ages 19-50 years - 18 mg/day
  • Women ages 51+ - 8 mg/day
  • Pregnant women - 27 mg/day
  • Men ages 19-50+ years - 8 mg/day
Best Food Sources of Iron
  • Lean red meat
  • Fish
  • Poultry
  • Liver
Other Food Sources of Iron
  • Iron-fortified cereals
  • Legumes
  • Beans
  • Dark-green leafy vegetables (e.g., spinach)
  • Blackstrap molasses
  • Dried fruit (e.g., raisins)
Factors Effecting Iron Absorption
  • Iron found in animal sources is better absorbed by the body because it is in the heme form (myoglobin and hemoglobin, like in our bodies) and, therefore, treated like a protein.
  • Iron found in plant sources is in the nonheme form which has to be released by digestive enzymes from the plant structures. Various factors decrease its absorption.
  • Consuming Vitamin C (approximately 25-75 mg of Vitamin C) can enhance your body's absorption of iron.
  • Cooking foods in a cast iron skillet increases absorbable iron, especially when cooking acidic foods such as tomatoes.
  • Caffeine, calcium, zinc, tannins (in tea), polyphenols, and phytates can interfere with the body's ability to absorb iron.
Reversing iron-deficiency anemia can take 3-6 months and may require taking iron supplements. However, you should consult your physician before taking iron supplements because iron toxicity can result. Under normal circumstances, very little iron is lost from the body and so taking an excess can lead to an accumulation in your body's tissues and organs. Abnormally high levels of iron are associated with an increased risk for Parkinsons' disease, cancer, and heart disease. Excessively high levels of iron can also cause congestive heart failure and irreversible liver damage.

If you suspect that you may have iron-deficiency anemia schedule an appointment with your physician. There may be causes of the anemia, other than dietary intake, that need medical attention.

Vegetarian Sports Nutrition - food choices and eating plans for fitness and performance, 2007; Larson-Meyer, D.E.

The Coaches Guide to Sports Nutrition, 2007; Benardot, D. and Thompson, W.R.

Office of Dietary Supplements of the National Institutes of Health, "Dietary Supplement Fact Sheet - Iron."

ACSM's Health & Fitness Journal, Vol. 9/Issue 2, "Avoiding Exercise-Related Fatigue," pp. 30-32, Rush, S.

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Anonymous Iron Supplements said...

I am a runner and didnt realise that my iron would be depleted through exercise and this led to me believing i had plateaued in terms of my fitness goals where in reality, little did i know that iron deficiency was the real cause! I am on iron supplements and my levels have come back up but now I have the added side effect of constipation, so i’ve adjusted my doses (as recommended by my nutritionist) and hopefully this will help to correct this - very worrying though for a while of feeling constantly tired and 'drained.


August 27, 2009 at 6:12 AM 
Anonymous Ola Loa said...

Very relevant post. There are many symptoms that occur with iron deficiency. Low back pain is one of the most common early signs. Iron is a catalyst to vitamin C in the formation of the connective tissue, collagen, that gives our tissues strength. The lumbar spine takes more mechanical stress than any other part of the body because so it is one of the first tissues to complain. Weak fingernails along with cupping of the nail shape also point to iron deficiency. Cracked lips and sore tongue occur because iron is a catalyst for riboflavin (vitamin B2), which produces nucleic acids for cell repair. Resistance to infection also declines when iron is unavailable to catalyze production of hydroxyl ions, one of the chief weapons of the antibacterial white blood cells (neutrophils).

The slogan "tired blood,” related to iron deficiency is somewhat misleading. Yes, anemia does occur. But the fatigue is usually caused by loss of iron activation of cytochrome enzymes that are the ultimate releasers of energy from the foods we eat. In addition iron is required as a catalyst to the production of adrenalin-like substances by nerve cells. Without iron, poor mental concentration and low mood are usual. In children, irritability, hyperactivity and learning impairment have been traced to iron deficiency in many cases.

If you're interested in the subject, I definitely recommend this article on iron deficiency by Dr. Richard Kunin.

September 4, 2009 at 2:12 PM 

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