From the November 2011 issue of Runner’s World
With 56 per cent of RW pollsters reporting an iron deficiency, we investigate how to beat the haemoglobin hazard
By Harriet Edmund
After a sluggish few weeks Karen Natoli got home from a tough Sunday morning long run and could barely keep her eyes open. She needed sleep – not unusual when you’re training for your third marathon of the season. But when she didn’t wake up until three hours later and still felt exhausted, she suspected her iron levels were low – again.
The 33-year-old has battled iron deficiency since she was a teenager, but when she took up running eight years ago, she soon learnt managing the common condition was vital to her performance on the track.
Iron helps runners transport oxygen in the body and makes up enzymes that produce energy. It also helps create red blood cells, boost immune and neuron health, plus thyroid hormone function. Without enough iron – and runners often need 1.3 to 1.7 times more than non-runners – you could find yourself burnt out, as Natoli did.
After winning her debut race, the 2006 Melbourne Marathon in 2:53:06, a lack of iron has forced Natoli to modify her training and meant she has hit the wall in many races. “It’s a fatigue that creeps up on you, but runners can avoid it with diet and rest,” she says.
Runners are at high risk of depleted iron stores, especially during intensive training periods, says Stephanie Gaskell, accredited practising sports dietitian for Optimal Endurance Nutrition (optimalendurancenutrition.com).
This is because iron is lost through sweat, urine, gastrointestinal tract bleeding (sometimes caused by taking anti-inflammatories), injury and damage to the red blood cells when your feet strike the ground called foot-strike haemolysis. Menstrual bleeding for women and rapid growth in adolescents can also deplete stores.
“It often depends on the duration and intensity of your training,” says Gaskell. “If you follow a moderate program that is not too strenuous, your iron status should not be significantly affected.”
For Natoli, clocking about 100 kilometres a week and her vegetarian diet was enough to see her iron levels plummet.
Iron deficiency impacts on a runner’s capacity to train, their work rate and energy efficiency, says Gaskell, particularly if it’s left untreated and progresses to iron deficiency anaemia (IDA). If this happens athletic performance can decrease by 20 per cent, according to Clinical Sports Nutrition by Louise Burke, of the Australian Institute of Sport.
On the lookout
If, like Natoli, you need more than just a cat nap after your Sunday long run, struggle to recover from training, lack energy during hard efforts, have shortness of breath, suffer heart palpitations and feel fuzzy in the head – you could be low in iron.
Gaskell warns when such fatigue sets in, runners can lack concentration at training, increasing the risk of injury. “Sometimes runners can also look pale, feel generally run-down, have mood swings and their appetite may decrease,” she says. However these symptoms can also be the result of overtraining, stress or lack of quality sleep making it important to and seek professional help from a medical practitioner or sports dietitian. A blood test can determine your levels of serum ferritin, transferrin saturation and total iron-building capacity.
Treat it right
Diet is the best way to get the iron you need to stay on track, but there are a few tricks to making the most of the energy packed fuel.
To get your recommended daily intake – eight milligrams for men and 18mg for women (27mg if you’re pregnant), be sure to include both haem and non-haem sources in your diet.
Haem iron is absorbed into your system up to five times more easily and should be eaten three to four times a week, says Gaskell. It includes lean lamb, beef, chicken and fish. While non-haem sources include iron-fortified cereals, beans, lentils, eggs, nuts and leafy vegetables (see “Lift Your Count” below).
To boost your absorption by up to four times, especially if you are vegetarian, try to combine your iron sources with Vitamin C rich foods such as citrus fruits and juices, tomatoes, broccoli, capsicum and strawberries, or Vitamin A packed foods such as yellow, orange and green fruits and vegetables.
And think twice about pouring a glass of wine with dinner and drinking coffee or tea afterwards, as these can reduce your absorption rate. “This is because red wine contains iron-binding compounds called polyphenols,” says Gaskell. Other natural compounds to avoid when eating iron are tannins found in tea and coffee, phytates and fibre in some cereals and legumes, oxalates in vegetables and phosphates in eggs.
Iron supplements can help boost stores, but seek medical advice because overuse can carry long term health risks, as a 2010 Swiss study found. After surveying 170 male and female Zürich Marathon participants, researchers discovered iron supplements were widely used in an effort to increase performance, particularly among male recreational runners. In fact, six runners showed signs of an unhealthy iron overload.
Natoli says her iron levels are restored thanks to the introduction of easy weeks after hard training blocks and red meat into her diet. “Now I can work on my speed and running a sub-2.44 marathon PB in early 2012.”
LIFT YOUR COUNT
How to get your recommended daily iron intake – eight milligrams for men and 18mg for women
PATE stacks 9.4mg of iron per 100 grams, but the liver-packed spread may not top your post-run menu. Try getting your iron from these more traditional sources instead.
3.8mg BEEF RUMP, 100g (cooked)
3.2mg LAMB STEAK, 100g (cooked)
1.5mg PORK, 100g (cooked)
1.0mg COOKED SKINLESS CHICKEN, 100g (cooked)
0.8mg FISH, 100g (cooked)
4.2-6.6mg CEREAL (iron fortified), 60g
4.4mg BAKED BEANS, 1 cup
4.0mg BREAD (with added iron), 2 slices
1.6-3.8mg CASHEWS/ALMONDS, 50g
1.7mg EGGS, 60g
2.1mg SWEETCORN, ½ cup
1.3mg BOK CHOY, ¾ cup
1.0mg BROCCOLI, 1 cup
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