Running is good for the heart, and it keeps you in shape – but it can also lower your iron level. Iron deficiency in runners is surprisingly common, especially younger women who run long distances. In some cases, iron stores are low enough to cause a running-related drop in red blood cell count – a condition called runner’s anemia.
Iron Deficiency in Runners: What Causes It?
There are several reasons why runners are more prone towards low iron levels. Some runners restrict calories to keep their weight down, and more than a few eat a vegetarian diet that’s low in iron. Anemia in runners is also more common because their feet constantly slap the pavement. This constant pounding causes destruction of red blood cells, which can ultimately lead to runner’s anemia.
Some experts believe that oxidative damage plays a role in runner’s anemia. Long-distance running and sprinting cause oxidative damage to red blood cells, which can lead to their destruction.
Runners who run long distances also lose iron through heavy sweating. This iron loss can add up over time ‘” especially if a runner runs several times a week. Hard exercise, in general, increases an athlete’s requirement for iron. Athletes who run longer, harder, and more intensely have greater iron requirements than those who run at a leisurely pace. Plus, runners don’t always eat a diet conducive to replacing lost iron stores.
Iron Deficiency in Runners Can Reduce Their Performance
Not only does iron deficiency cause fatigue, it reduces running performance. Iron has the critical job of supplying cells with oxygen, and if muscle cells don’t have enough oxygen during exercise, they produce lactic acid. When lactic acid builds up, it causes muscle fatigue, which isn’t a good thing if you’re a runner. One study showed runners who supplemented with 100 milligrams of ferrous sulfate for six weeks, had better endurance and less muscle fatigue even if they didn’t have low iron levels.
Low Iron Levels in Runners: The Bottom Line?
Iron deficiency and runner’s anemia are common in athletes, particularly females, vegetarians, and those who run a lot of miles. If you’re a runner, it’s a good idea to get an iron panel checked every six months, and, if necessary, alter your diet to get more iron. Not only will it make you feel better – it could also boost your running performance.
Medscape.com website. “Nutrition and Athletic Performance”
J Appl Physiol 94: 38-42, 2003.