N U T R I T I O N Beat fatigue with iron-rich foods
To maintain a high level of energy for training and competition, your body needs a good supply of this essential mineral by Shawn Hueglin
IRON IS A MINERAL THAT PLAYS AN important role in athletic performance. Iron’s main functions are to transport oxygen throughout the body and aid in the production of red blood cells. Oxygen is transported through the body by hemo- globin, a protein found in red blood cells. One of the crucial components of hemo- globin is iron. In order for oxygen to attach to he-
moglobin, iron must be present. Muscles require oxygen to contract, so optimal iron levels within the body are critical to perform well in volleyball.
What are the symptoms of iron deficiency? What are the symptoms of iron defi-
ciency? • Breathlessness or early fatigue during
training. • Reduced motivation to train. • Increased rate of perceived exer-
tion (RPE) – training feels harder than it should. • Decreased aerobic capacity. • Decreased ability to adapt to training.
What might cause iron deficiency? • Low overall calorie consumption and/or
chronically low carbohydrate consumption. • Low intake of animal protein. • Excessive blood loss (menstruation, in-
jury/disease or gastrointestinal trauma). • Poor absorption of iron due to interaction with food or medication. • Excessive iron loss through sweat, feces and urine during periods of heavy training. • Overuse of anti-inflammatory drugs (e.g.
NSAIDs). • Foot strike hemolysis (repeated pounding of the feet on hard surfaces, causing damage to red blood cells and iron loss.)
How much iron do you need? For an athlete with adequate iron levels, the
daily recommended intake (DRI) is: • Females (18-50 years old) – 18 mg • Males (18-50 years old) – 8 mg
For athletes with iron deficiency (based on
results from a blood draw), daily iron needs are higher and often cannot be met with food
Food sources of iron Food sources of heme iron Oysters – 3 oz.
Lean beef steak – 3.5 oz. Egg, whole
Lean pork/ham – 3.5 oz. Tuna, cooked – 3.5 oz.
Salmon or chicken breast – 3.5 oz. White fish – 3.5 oz.
Food sources of non-heme iron Fortified cereal – 1 cup Tofu, raw – ½ cup Lentils – 1 cup
Oatmeal, instant (1 pkg); Sport bar (1) Kidney or garbanzo beans – 1 cup Black beans – 1 cup
Spinach, cooked – ½ cup White pasta or rice, cooked – 1 cup
Iron (mg) 7.8 3.8 1.7 1.5 1.1
0.9 - 0.8 0.4
Iron (mg) 4.5 – 18 6.7 6.6 6.3
5.2 - 4.8 3.6 3.2 1.9
Dried figs (4) or dried apricots (10 halves) 1.7 Raisins – cup
1.0
alone. A sports medicine physician or sport dietitian can help advise and monitor iron supplementation.
How do you ensure adequate iron intake? Luckily, many foods contain iron, including meat, fish and poultry, fortified cereal, veg- etables and food cooked in cast iron cookware. Iron from animal sources is highly absorbed by the body and is called heme iron. Iron from sources such as dark leafy greens, fortified cereals, sports bars, fruits and vegetables is poorly absorbed by the body; this type of iron is known as non-heme iron. Adding food rich in vitamin C to your non-heme iron source is a simple strategy to facilitate absorption. For example, add strawberry slices to your cereal or lemon juice to your lentils to enhance absorp- tion. Other good sources of vitamin C that can help absorption include pineapple, orange, grapefruit (and their juices), peppers, broccoli, tomato and kiwis. The table below lists the iron content of
an assortment of both heme and non-heme iron sources, along with considerations for iron absorption.
56 | VOLLEYBALLUSA • Digital Issue at
usavolleyball.org/mag
What foods inhibit iron absorption? • Calcium rich foods, tea, coffee and cocoa can inhibit heme iron absorption. • Certain types of fiber found in spin- ach, kale, walnuts and almonds can inhibit the absorption of non-heme iron.
How does following a plant-based diet impact iron absorption? Vegetarian and vegan athletes consume most, if not all, of their iron sources from non-heme foods and need to take extra care to ensure they optimize iron intake and absorption. Below are some meal and snack suggestions that will ensure athletes on a vegetarian or vegan diet eat and absorb enough iron. • Include iron-rich foods such as fish,
poultry, fortified cereal or tofu in two meals per day to meet recommendations. • Pair dried fruits like figs and apricots
with hard-boiled eggs for an iron-rich snack.
• Boost iron at breakfast by topping oatmeal with 1/3 cup of raisins plus a small glass of citrus juice.
• Make an iron-rich brown rice bowl by combining black beans, tofu and veggies. • Make lentil and spinach tacos with a citrus slaw to enhance absorption for an iron-rich dinner. • Prepare a batch of tuna salad for sand-
wiches throughout the week to ensure daily iron intake.
• Choose the highest percentage iron forti-
fied cereal. Check labels. • When possible, cook foods in a cast iron
pan.
• Avoid drinking tea or coffee with meals containing rich sources of iron. Iron is a crucial element in any diet, but especially an athlete’s diet. By ensuring optimal daily doses of nutrients rich in iron, you are allowing yourself to train and compete at your optimal level.
Shawn Hueglin, PhD, RD, CSSD is a sport dietitian with the United States Olympic Com- mittee. She works primarily with team sports based in the Los Angeles area and the U.S. Olym- pic Training Center in Chula Vista.
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