Iron and training: signs, food and testing

Who is most at risk

Anyone can become low in iron, but some groups are more likely to:

• Women with periods, especially heavy periods, who lose iron every month
• Pregnant women, whose iron needs rise significantly
• Runners and endurance athletes, who lose small amounts through sweat, the gut and the impact of running, and absorb less iron for a few hours after hard sessions
• Vegetarians and vegans, because plant iron is less well absorbed
• Regular blood donors
• People who restrict food, including those dieting hard while training
• People with conditions affecting absorption, such as coeliac disease

Hybrid and HYROX training, with its mix of running and hard conditioning, puts people in several of these groups at once. Our nutrition for HYROX training guide covers the wider fuelling picture.

Signs you might be low

The NHS lists these as common symptoms of iron deficiency anaemia:

• Tiredness and lack of energy
• Shortness of breath
• Noticeable heartbeats, or palpitations
• Pale skin

Less common signs include headaches, a sore or smooth tongue, hair loss, mouth ulcers, restless legs, and craving non-food items such as ice. In training, people often describe heavy legs, a heart rate that climbs quickly at easy paces and an inability to recover between efforts.

These symptoms overlap with lots of other causes, including poor sleep, under-eating, overtraining and illness. That is why a blood test matters. Our guide to overtraining covers some of the other possibilities.

Getting tested

If you think you might be low, see your GP. A blood test usually includes a full blood count, which shows whether you are anaemic, and often ferritin, which reflects your iron stores. Tell your GP that you train regularly, as it helps them interpret the results.

Iron deficiency in men and in women after the menopause should always be investigated, because it can be a sign of bleeding from the gut or another condition that needs treatment. Do not simply treat it yourself with supplements.

Food sources and absorption

There are two types of iron in food. Haem iron from meat and fish is absorbed well. Non-haem iron from plants and fortified foods is absorbed less efficiently, but you can improve how much you take in.

• Haem iron: red meat, dark poultry meat, liver (not during pregnancy), sardines, mussels and other shellfish
• Non-haem iron: beans, lentils, chickpeas, tofu, tempeh, fortified breakfast cereals, dark green leafy vegetables, dried apricots, nuts, seeds and wholemeal bread

Simple ways to absorb more:

1. Pair plant iron with vitamin C: peppers, tomatoes, citrus fruit, berries or a small glass of orange juice with the meal.
2. Keep tea and coffee away from iron-rich meals, ideally by an hour or so, as they reduce absorption.
3. Add a small amount of meat or fish to plant-based meals if you eat them, which boosts absorption of the plant iron too.
4. Avoid taking calcium supplements at the same time as iron-rich meals or iron tablets.

The NHS advises that people eating more than 90 g of red and processed meat a day cut down to 70 g. You do not need large amounts of red meat to get enough iron, especially if you use the absorption tips above. Plant eaters can find more in our guide to vegetarian and vegan protein.

A day that covers iron well might look like fortified cereal with berries at breakfast, a lentil and vegetable soup with wholemeal bread at lunch, a handful of dried apricots and nuts in the afternoon, and a beef or tofu stir fry with peppers and broccoli for dinner. Tea and coffee go mid-morning and mid-afternoon rather than with meals.

Supplements: only with advice

If a blood test confirms you are low, your GP may prescribe iron tablets and recheck your levels after a few months. Common side effects include constipation, stomach upset and dark stools. Taking them on alternate days, or with a little food, can help some people, but follow your GP's advice.

Taking iron supplements without a confirmed need is not a good idea. Iron overload is possible, and a genetic condition called haemochromatosis, which causes the body to store too much iron, is relatively common in people of northern European descent. The NHS advises that 17 mg a day or less from supplements is unlikely to cause harm, and higher doses should only be taken on medical advice.

Keep iron tablets well out of reach of children. An overdose can be very dangerous for young children, so call 999 or go to A&E if a child swallows them.

Low iron is one reason training can feel unusually hard, and it is worth ruling out before assuming you are unfit. Women who train have more to consider, covered in nutrition for women who train. And if you want training that can be scaled while you get your energy back, every class at Lycan Strength can be adjusted to how you feel on the day.