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The Feedzone with Monique Ryan: Are you getting enough iron?
Adequate intake is essential to prepare for the 2007 season.
Cyclists in many parts of the country are ready to leave behind long rideson the trainer and eagerly await warmer weather and putting in some qualityroad miles. As you continue to train and prepare for the 2007 season, don’tignore a small, but essential component of your training diet. Adequateiron intake and optimal iron stores are essential to putting in full effortson the bike. Low iron stores can impair athletic performance, and correctingiron deficiency that has led to full blown anemia, can take several monthsto correct, potentially bringing an unwelcome halt to your training andracing program.Why you need iron
Iron is required for a number of important exercise related functionsin the body. It is an important component of hemoglobin, which transportsoxygen in the blood. Iron is also an important component of myoglobin,which transports oxygen in the muscles. Many muscle enzymes involved inmetabolism require iron, and other iron compounds facilitate oxygen useat the cellular level. And if that weren’t enough to convince youthat you should pay attention to this all-important mineral, iron is alsorequired for red blood cell production and is essential to maintaininga healthy immune system.Data clearly indicates that true iron-deficiency anemia, the extremeof low iron stores in the body, will impair your performance. Althoughwe have limited data on the performance effects of early iron deficiency(before true anemia develops), some newer research suggests that correctingthis state can also prevent a downturn in performance. Of course, it isalso prudent to treat early iron deficiency in order to prevent the moreserious condition of anemia from developing.Getting checked
Your body’s storage form of iron, ferritin, is used as an indicatorof iron stores, as are other iron measures- serum iron, transferrin, transferrinsaturation, hemoglobin, and hematocrit. About 30 percent of iron is instorage form and the remaining 70 percent of your iron is involved in oxygentransport.Many athletes have these iron-related values checked regularly at variouspoints in their training and competitive season. A skilled practitionercan evaluate these values in conjunction with a dietary assessment andongoing monitoring. At this point in the season, it would be prudent toobtain some baseline values, particularly if you have not had them checkedin sometime. Regular monitoring of blood work can then reveal individualtrends and potential problems. Iron depletion is a continuous process thatcan eventually result in iron deficiency anemia, a condition under whichyour ability to manufacture hemoglobin and red blood cells is limited.If not detected early, iron depletion can easily lead to anemia.Endurance training can also affect your blood measurements of iron.Training produces an increased blood volume, which dilutes hemoglobin,making it appear low in some athletes when iron stores are adequate. Thisincreased blood volume usually occurs at the beginning of serious trainingand is another reason why it is so important to check several iron storesand monitor individual changes.Why you might be at risk
Inadequate dietary intake of iron is the most common cause of irondeficiency and anemia. As a cyclist you do have high iron requirementsand need to maintain a high level of red blood cells. Younger cyclistsalso have higher iron needs during periods of growth. Iron losses can alsoaggravate iron balance. Iron is lost in sweat, and the higher your sweatrate, the greater your iron losses. Strenuous training can also precipitategastrointestinal bleeding from minor damage to the stomach and intestinallining. Habitual use of anti-inflammatory drugs can also cause some gastrointestinalblood loss. For cyclists who cross train, repeated pounding of the feeton hard surfaces, such as when running, can also destroy red blood cells.Training at altitude can also place you at risk for iron deficiency.Iron in your diet
Our bodies can’t manufacture iron, so we do need to obtain this mineralfrom our diet. Development of iron deficiency is associated withlow calorie diets, diets with limited amounts of animal protein, poorlyplanned vegetarian diets, and various types of fad or unbalanced diets.Iron is actually found in a variety of foods, but some foods are moreconcentrated sources of iron, and some have a better “bioavailability,”or simply provide a better absorbed form of iron. The best food sourcesof iron provide an ample amount of this trace mineral and in a well-absorbedform. Many foods are also fortified with iron. Heme iron, found inanimal foods such as lean meat, poultry, and seafood is the best absorbedform with a 10 to 30 percent absorption rate, while non-heme iron foundin plant foods such as dried peas and beans, and whole grains, has a 2to 10 percent absorption rate.They are several ways to increase your iron intake and maximize youriron absorption. Consuming meat and plant iron sources together can enhanceiron absorption from plant foods. Small amounts of red meat or poultryin bean chili, spinach with chicken, and turkey in lentil soup are examplesof combining heme and non-heme iron. Vitamin C containing foods also enhanceplant iron absorption. Try having orange juice or strawberries with aniron-fortified cereal.To boost iron intake and absorption, you can also:
• Incorporate small amounts of lean red meat into your diet.
• Add small amounts of red meats to stir-fries, soups, pasta sauces,and casseroles.
• Mix heme iron foods with non-heme iron foods.
• Incorporate iron fortified cereals into your diet. Avoid cerealswith a high bran content, as they contain phytic acid, which binds withiron and decreases absorption.
• Add more fish and shellfish to your diet for their iron content.
• Avoid drinking strong tea and coffee with iron-rich meals, as theycan inhibit iron absorption.
Iron Content (mg) of Selected Foods
| Sources of Heme Iron | Iron |
| Liver, beef, cooked, 3 oz. 100 g) | 6.0 |
| Beef, cooked, 3 oz. (100 g ) | 3.5 |
| Pork, cooked, 3 oz. (100 g) | 3.4 |
| Shrimp, cooked, 3 oz. (100 g) | 2.6 |
| Turkey, dark, cooked, 3 oz. (100 g) | 2.0 |
| Chicken, breast, cooked, 3 oz. (100g) | 1.0 |
| Tuna, light, 3 oz. (100 g) | 1.0 |
| Flounder, sole, salmon, 3 oz. (100 g) | 1.0 |
| Sources of Plant Iron | Iron |
| Cereal, iron-fortified, 1 oz (30 g) | 2–18 |
| Cream of wheat, 3/4 c. (200 ml) | 9 |
| Lentils, 1 c. (240 ml) | 6 |
| Instant breakfast, 1 envelope | 4.5 |
| Kidney beans, canned, 1 c. (240 ml) | 3.2 |
| Baked potato, with skin, 1 | 3.0 |
| Prune juice, 8 oz. (240 ml) | 3.0 |
| Wheat germ, 1/4 c. (60 ml) | 2.6 |
| Apricots, dried, 10 halves | 1.7 |
| Spaghetti, enriched, cooked, 1/2 c. (120 ml) | 1.4 |
| Bread, enriched, 1 slice | 1.0 |
Besides an iron rich diet, iron supplementation may be needed to bringback iron stores to normal. Athletes are typically supplemented with 100to 300 milligrams of iron combined with vitamin C to enhance absorption.Iron supplementation should always be done with regular medical monitoring.You should never diagnose an iron deficiency on your own or supplementto prevent a perceived deficiency. While the amounts of iron found in abasic multivitamin mineral supplement are modest, ranging, from 8 to 18milligrams, higher doses can pose some risk. High doses of unneeded ironcan actually compromise your immune system, and could interfere with zincand copper absorption. A small percentage of people also have a conditioncalled hemochromatosis. In this potentially dangerous condition iron accumulatesin your tissues and organs often causing irreparable damage. This conditioncan go undiagnosed for many years, and is aggravated by unneeded iron supplementation.
Monique Ryan, MS, RD, LDN is a nationally recognized nutritionistwith over twenty-two years of experience and is owner of Personal NutritionDesigns,
a Chicago based nutrition consulting company that provides nutritionprograms for endurance athletes across North America (www.moniqueryan.com).Monique consults with the Chicago Fire Soccer Team, and was the nutritionistfor Saturn Cycling from 1994 to 2000. She has also consulted with the Volvo-CannondaleMountain Bike Team, the Gary Fisher Mountain Bike Team, and the RollerbladeRacing Team. Monique has consulted with USA Cycling, and was a member ofthe Performance Enhancement Team for the Women’s Road Team leading to the2004 Athens Olympics. She has also provided nutrition consultation servicesto USA Triathlon for coaching clinics, athlete clinics, and for the residentathlete team and was a member of the USAT Performance Enhancement Teamfor the 2004 Athens Olympics. Monique is the author of "SportsNutrition for Endurance Athletes," 2nd edition (March 2007), from VeloPress,which provides sports specific nutrition for road cycling, mountain biking,running, triathlon, swimming, rowing, and adventure racing. She is alsoauthor of "PerformanceNutrition for Winter Sports" (PeakSports Press), "Performance Nutritionfor Team Sports" (PeakSports Press), and "Complete Guide to Sports Nutrition."Monique is a regular contributor to VeloNews, Inside Triathlon,Outside, and ACE Fitness Matters. As part of the FeedZonecolumn, Monique will answer selected questions online. Please sendyour questions to RyanWebQA@aol.com.
