IRON
& SPORT
Are you getting enough iron?
For those who participate in regular intensive exercise - both at
the recreational and elite level - there is a risk of depleting iron
stores and in some cases developing iron deficiency anaemia. When
people train regularly their requirements increase and they may
have higher iron losses than those who are inactive.* It is therefore
important for all athletes to be conscious of their iron needs, particularly
those who follow vegetarian, vegan or low energy diets.
WHAT DOES IRON DO?
Iron is a mineral that has several
important functions in the body.
Iron is:
- Needed to make new blood cells
- Part of haemoglobin which carries
oxygen in the blood
- Part of myoglobin which helps oxygen
be transported into the muscles
- Important to maintain the release of
energy needed to support aerobic
and endurance training
- Required for a healthy immune system
As the body is unable to manufacture
iron, it is important that the food we
eat supplies enough to meet our
requirements.
HOW DO YOU KNOW IF YOU’RE
NOT GETTING ENOUGH IRON?
The physical symptoms of iron depletion
can include feeling tired, looking pale,
having a decreased appetite, increased
duration of colds and infections and an
elevated heart rate. As well as considering
physical symptoms, blood tests can be
performed to investigate the amount of
iron circulating in your bloodstream, the
amount you have in your body stores,
and how well iron is being absorbed and
transported around your body. From these
tests, a medical professional will be able to
determine the level of depletion and the
action required. It is important to monitor
the iron in your diet because even in the
early stages of iron depletion, your sports
performance can be compromised.
HOW MUCH IRON DO
YOU NEED?
The following table shows the
Recommended Daily Intake for the
average New Zealander.
AGE
9-13 years***
14-18 years***
Adults (19-50 years)***
Adults (50+ years)***
Pregnant***
The specific requirements for athletes
are not known but it has been
suggested that iron requirements
maybe around 1.3 - 1.7 times the
figures in the table below.**
MALE
FEMALE
8mg/day
11mg/day
8mg/day
8mg/day
-
8mg/day
15mg/day
18mg/day
8mg/day
27mg/day
By Nutritionist Claire Turnbull - www.claireturnbull.co.nz
WHY DO SPORTS PEOPLE
NEED MORE IRON?
There is a high demand for iron:
• Intensive training increases the number
of red blood cells and blood vessels
in your body, and therefore you need
more iron to supply to the new cells
• Sports people may go through periods
of growth which increases their need
for iron
Sports people may have inadequate iron
in their diet. This is particularly significant for
those who:
• have an energy (kJ) restricted diet
• have poorly balanced vegetarian/
vegan diets
• eat very little red meat, chicken, fish,
eggs or iron fortified breakfast cereals
Sports people can often have high losses
of iron from:
• Blood loss through injury, nose bleeds
and menstruation
• Blood lost through gastrointestinal
bleeding. This can occur during very
heavy or hard training e.g. marathons,
Ironman
• Mechanical trauma such as footstrike
haemolysis (repeated pounding of
feet on hard surfaces) can destroy red
blood cells which in turn increase the
loss of iron
• Sweating heavily – iron is lost in sweat
HOW IS IT TREATED?
Treatment for diagnosed iron deficiency
firstly requires dietary intervention to
increase the intake and absorption of iron
from food. Iron supplements may also be
required if iron stores are very low and
the body reaches a state of deficiency.
This should be discussed with a medical
practitioner as the inappropriate use
of iron supplements can cause other
problems, including interference with the
absorption of minerals such as zinc and
copper, as well as potentially having a
negative effect on the immune system.
WHAT ARE THE BEST
SOURCES OF IRON?
Iron absorption is best (15-35%)*** from
foods that contain haem iron. Red meat
(beef, lamb and venison) are by far the
best sources, followed by poultry and
seafood. Non-haem iron is less easily
absorbed on its own (2-15%)*** but can
be enhanced when eaten at the same
time as haem iron or vitamin C rich food
or drink. Non haem iron is predominately
found in plant foods including bread,
cereals, pulses, vegetables and nuts.
Serving these foods with a small glass of
fruit juice, squeeze of lemon juice or piece
of fruit can add that boost of vitamin C to
help increase iron absorption.
TIPS TO PREVENT AND TREAT
IRON DEPLETION
• Eat iron rich foods every day
• Eat lean red meat at least three times a
week
• Choose breakfast cereals with added
iron
• Include vitamin C rich foods in your
meals to enhance the absorption of
iron e.g. oranges, berries, lemon juice,
kiwifruit, fruit juice, capsicum and
broccoli
• For vegetarian meals include nonhaem iron sources such as beans, peas
and lentils and serve with vitamin C rich
foods
• Avoid strong tea or coffee with meals
as they can reduce iron absorption
IRON CONTENT OF FOOD:
ANIMAL SOURCE
SERVING SIZE
IRON PER SERVE (mg)
Lean, cooked lamb
Lean, cooked beef
Lean, cooked pork fillet
Chicken breast/thigh, cooked
Fish (fresh grilled), canned tuna or
salmon
Egg (boiled)
100g
100g
100g
100g
5.4
3.4 - 3.7
1.5
0.8 - 1.0
100g
0.8 - 1.0
1 egg
0.9
PLANT SOURCE
SERVING SIZE
IRON PER SERVE (mg)
Breakfast cereal (with iron added)
Nuts (cashews, almonds)
Baked beans
Corn
Porridge, cooked oats
Bread (wholemeal/wholegrain)
Green vegetables (broccoli,
spinach, silverbeet, cabbage,
Chinese greens)
Potato (boiled)
Pasta/noodles, cooked
Dried fruit (prunes, apricots)
Fresh fruit
1-1.5 cups (50g)
50g
1/2 cup (120g)
1/2 cup (120g)
1 cup (260g)
2 slices (60g)
3.8 - 5
1.6 - 3.1
2.2
2.1
1.3
1.1 - 1.4
1/2 cup (120g)
0.8 - 1.2
150g
1 cup (50g)
5-6 (50g)
1 average piece
0.7
0.6
0.6
0.3 - 0.5
* Nutrition for Athletes 2012. A practical guide for health
and performance. Vitamins, Minerals and Phytochemicals
– Iron Pg 30. International Olympic Committee
** Louise Burke et al 2006. Clinical Sports Nutrition, 3rd
Edition, Iron deplection in athletes, pg 272 - 291
*** http://www.nrv.gov.au/nutrients/iron.htm
†
Louise Burke et al 2006. Clinical Sports Nutrition, 3rd
Edition, Iron deplection in athletes, pg 272
By Nutritionist Claire Turnbull - www.claireturnbull.co.nz
For more information and to obtain further copies
of any of the Eating for Your Sport Nutrition Advice
sheets, visit www.nutrition.nestle.co.nz
or www.autmillennium.org.nz/nutrition
© Nestlé New Zealand Limited &
AUT Millennium. Issued September 2014