Iron and athletes? Lots of talk about it but what are the facts? Why is it important? Where do we get it from? How much do we need and how do we know if we need more?
Iron has many key roles in the body- from building enzymes to being essential to manufacture haemoglobin which transports oxygen from the lungs to the blood. It’s also really important in immune function and the mitochondria in muscle cells need it when the enzymes burn fuels with oxygen in.
Your body can’t create iron, so it needs to get it from dietary sources. There are two main sources: ‘heme’ which is mainly from meat and animal sources and ‘non-heme’ which is sourced from vegetables, grains and pulses. In general, non-heme is less bioavailable than heme so vegetarian and vegans need to be careful about nutrition.
How much do we need? Like anything in science, it depends... The guidelines state males need 8mg a day and females need 18mg, predominantly due to menstruation losses but also the surges in progesterone in the menstrual cycle causes a reduction in iron absorption in the gut. But athletes need much more- as iron is lost in sweat, foot strikes, muscle damage and eccentric exercise like changes in direction and running downhill. Iron absorption can also be reduced when athletes don’t eat enough to fuel their training, when they are on a low carb-hight fat or keto diet or when progesterone levels are high at certain points of the menstrual cycle.
What else can affect iron? What and when we eat is important, it’s well known that iron absorption is reduced if tannins from tea and coffee are present and increased if vitamin C is taken at the same time. Iron uptake is also reduced by a key hormone called hepcidin which varies over the day and after exercise.
How do we know if we are iron deficient? The earliest stage is ‘iron depletion’ of stores but haemoglobin hasn’t been impacted. An athlete may be able to perform but will feel tired, sessions feel harder and they don’t bounce back after recovery.
How can we make sure we have enough iron? The answer is your diet. Does it contain enough iron and are you timing your food around hepcidin levels to ensure it’s absorbed?