Iron deficiency may slow down athletes, impair training and just making working out harder than it needs to be.
The Iron part of anemia, iron deficiency and athletes
Iron is important for athletes as well as everyone else. Iron is needed for formation of Hemoglobin. Hemoglobin is the molecule in blood cells that transports oxygen through blood. People who have low levels of red blood cells are said to be anemic. Anemia can be caused by many different things. This article, however, will focus on anemia caused by nutritional deficiency.
Iron deficiency can slow you down and make your workouts harder and more frustrating than they need to be. People who are iron deficient (or anemic) don’t carry oxygen efficiently. The heart has to work harder to get oxygen to tissues. Low oxygen can also cause “poop out” (just too tired to continue the workout). No need to mention this . . . but . . . an iron deficient person is not likely to compete well either. Anemia is most common in women of reproductive age. Recommended intake of iron is 8mg/day for men and post-menopausal women. It is 18/mg/day for women who are menstruating. Iron deficiency anemia (anemia not caused by blood loss, injury, illness of metabolic disorder) is highest among women of reproductive age. It is uncommon in young men and boys and more common in people over 50. About 7% of masters adults may have iron deficiency anemia. (Looker et al. 1997)
The athlete part of athletes iron and nutrition
There have been a number of studies of iron intake and exercise performance in animals and in people. Performance related studies have looked at work performance, fatigue, endurance, oxygen use and heart rate (McClung & Murray-Kolb2013) Iron supplementation has been associated with:
- Increased maximal exercise performance
- Increased VO2 max (maximal oxygen consumption
- Lower heart rate
- Less fatigue
- More voluntary activity
- Improved work performance
- Improved performance on fitness tests
- Increased energy expenditure
Intense training can lead to anemia. The popular term for training-induced anemia is Sports Anemia. Possible causes are intestinal bleeding, iron loss through perspiration, inflammation and a generally faster rate of body iron turnover. Many athletes (especially older athletes) use ibuprofen to cope with muscle soreness and aches and pains from injuries. Chronic use of aspirin and ibuprofen can increase risk of iron deficiency because they can cause stomach bleeding.
Iron deficiency can cause some cognitive problems too. These include spatial ability, attention, memory, executive functioning and planning. These abilities are important in everyday life. They are also abilities that are essential to training and competition.
The nutrition side of athletes, iron and nutrition
Iron-rich foods include:
- red meat
- dried fruit
- whole grains
- molasses (black strap style)
Other nutritional deficiencies can also make you vulnerable to iron deficiency even if you are getting enough iron. Vitamin C and Folate are important too. Low vitamin B12 also increases risk of anemia. There are a lot of interactions among Vitamin C, Vitamin B12, and Folate that are still poorly understood. High folate combined with low B12 increases the risk of anemia and risk of cognitive impairment in older people. Normal B12 and High Folate, on the other hand, protect against anemia and cognitive problems (Morris et al. 2007). Annoying that there no simple answers. The best strategy seems to be to eat a varied diet
Use pain relievers in moderation. Consider an iron supplement and make sure you are getting enough folate and vitamin C. Don’t over do iron intake. There is no evidence that extra iron will help you if you don’t need it. Too much iron can cause damage on its own.
Andrea Kirk, MSc. PhD is a toxicologist affiliated with the University of Texas at Arlington’s Department of Chemistry and Biochemistry and the University of North Texas Health Sciences Center‘s School of Public Health. Dr. Kirk does research on human exposures to environmental contaminants and micro-nutrient intake and excretion. She is also a former whitewater, dog-sledding, ice-climbing instructor and back-country ranger turned box rat.
Looker, A. (1997). Prevalence of Iron Deficiency in the United States JAMA: The Journal of the American Medical Association, 277 (12) DOI: 10.1001/jama.1997.03540360041028
Morris MS, Jacques PF, Rosenberg IH, & Selhub J (2007). Folate and vitamin B-12 status in relation to anemia, macrocytosis, and cognitive impairment in older Americans in the age of folic acid fortification. The American journal of clinical nutrition, 85 (1), 193-200 PMID: 17209196
McClung JP, & Murray-Kolb LE (2013). Iron nutrition and premenopausal women: effects of poor iron status on physical and neuropsychological performance. Annual review of nutrition, 33, 271-88 PMID: 23642204
Pasricha SR, Low M, Thompson J, Farrell A, & De-Regil LM (2014). Iron Supplementation Benefits Physical Performance in Women of Reproductive Age: A Systematic Review and Meta-Analysis. The Journal of nutrition PMID: 24717371