A journal of running, healthy food, mountains, bikes and technology by Julia Revitt

Having the correct amount of iron in your diet and therefore in your body directly relates to your athletic performance. Even just having a small deficiency will affect you. A study in the USA showed that 12% of women had a small deficiency! A lack of iron can also cause problems with frequent coughs, colds and viruses. Just drinking a glass of fresh orange juice with your meal can make a huge difference – find out why…

Oxygen and carbon dioxide are carried around the body from the lungs to the muscles and other body tissues attached to red blood cells. Iron in the diet is converted into the ‘heme’ and the oxygen and carbon dioxide attach themselves to heme for transport. The oxygen cannot reach your muscles if your diet is deficient in iron regardless of how much you inhale. Carbon dioxide cannot be efficiently be removed from your muscles regardless of how much you exhale.

Iron is a vital component of the immune system. A lack of iron can cause problems with frequent coughs, colds and viruses.

The recommended levels of iron are 8.7mg for men and post menopausal women and 14.8 for pre menopausal women. Excellent sources of iron include (per 100g):

  • Red meat (beef – 4mg)
  • Liver (beef liver – 7mg) (should be avoided by pregnant women due to vitamin A content)
  • Beans (kidney beans – 9mg)
  • Seeds (sesame seeds – 15mg)
  • Nuts (cashew needs – 7mg)
  • Dried fruit (dried apricots – 6mg)
  • Wholegrain foods (wholegrain bread & pasta & brown rice) (brown rice – 2mg)
  • Breakfast cereals fortified with iron (Kelloggs complete oat bran flakes – 63mg)
  • Soya products (soya beans – 16mg)
  • Dark green leafy vegetables (kale – 1.7mg)
  • Eggs (0.8mg per medium egg)

As you can see from the above list, iron enriched cereal is a great way to boost your daily iron intake.Refined foods generally have had many vitamins and minerals removed from them, so the enriched cereal has only had iron added in as it was removed in the first place. Try to eat unrefined foods such as wholegrain bread and pasta, brown rice, beans, nuts, seeds and plenty of fresh fruit and vegetables.

Increasing your iron intake can reduce the amount of zinc that is absorbed from the diet. So it is important to eat plenty of zinc along with iron – recommended intakes are 4 – 7mg for women and 5.5 – 9.5mg for men.Good sources of zinc include (per 100g);

  • Red meat (beef -8mg)
  • Breakfast cereals enriched with zinc (Kelloggs complete wheat bran flakes – 53mg)
  • Fish (oysters 53mg)
  • Legumes (peanut butter 15mg)
  • Wholegrain foods (rye flour 6mg)
  • Mushrooms (shiitake mushrooms 8mg)
  • Seeds (pumpkin seeds 10mg)
  • Beans (adzuki beans 5mg)

The absorption of iron is increased when vitamin C is consumed at the same time as the iron. For example, have a glass of fresh orange juice with the iron enriched cereal or have kale with your beef. Coffee and tea interfere with the absorption of iron, so try not to drink either with or within 90 minutes of eating.

Iron from animal sources tends to be more easily absorbed that iron from vegetable sources. If you are a vegetarian, you need to pay special attention to your iron intake. Make sure you have plenty of different sources of iron and try to have plenty of vitamin C with your meals.

Red meat tends to be high in saturated fat, so it is important to choose lean cuts of meat and remove any visible fat before cooking. Stay away from heavily marbled cuts of meat.


A lack of iron in the diet causes tiredness but can also lead to anemia. Symptoms of anemia include;

  • Pale skin
  • Tiredness
  • Feeling cold
  • Loss of appetite
  • Nausea

Anemia can also be caused by a lack of vitamin B12 or folic acid. It is therefore important to see your doctor if you suspect you may have anemia so that the cause can be identified.

People who are particularly at risk of anemia are;

  • Menstruating females (lose iron in their monthly cycles and if this is not replaced in the diet can lead to anemia)
  • Vegetarians (who do not have a balanced diet may not be consuming enough iron)
  • Endurance athletes (lose iron in their sweat and prolonged events can cause a deficiency)
  • Marathon runners (can damage their red blood cells through the pounding of their feet during training and the race. These damaged cells are removed from the blood and need to be replaced)
  • Teenagers (needs change rapidly and their diet needs to change with them as they grow. Teenage girls may need to increase their iron intake when they start menstruating.)

Iron supplements should only be taken on the advice of your doctor. Having too much iron in the body can cause nausea, vomiting, constipation and stomach pain and can ultimately be fatal.