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“I felt like I just couldn’t hit 4th gear...” -40 year old male competitive endurance runner Last summer, I was literally flagged down one sunny, Sunday morning while out riding my bike. I heard a male voice, floating out of a passing car window “Hey Donna”! It was an acquaintance of mine, someone I knew as a pretty serious Master’s level athlete. “I think I need your help”. I must have looked skeptical, because he rushed on, “No, seriously - I’ve been doing a lot of running, and there is something definitely wrong. I’ve been noticing this over a period of about six months”. He went on to describe how he felt. “It’s like I just can’t hit 4th gear, there’s no kick, nothing extra”. I nodded. “What makes you think it is your diet?” was my first question. “What about stress, or overtraining?” He assured me he had considered those things, but no - it couldn’t be. “Just check my diet out for me, O.K.?” Since he was a bachelor, I decided maybe he could use a little help. But athletic, 40 year old males shouldn’t really be feeling “slow, with no spark”, so I urged him to get some lab work done and see a physician. Then I would look at his diet. Being a male, of course he didn’t get his lab work done, but I agreed to review his diet anyway. It was all carbs. “I eat chicken” he protested when I told him he had too little protein. Yes, I conceded he did. But there were there were other concerns: lots of quick, fast food meals, too little food at noon, and calorie splurging on oversized bakery cookies after workouts. “Try a protein supplement like GenisoyÒ or a Met-RxÒ bar in the morning if you can’t do egg beaters. And eat a whole can of tuna at lunch, not just a half. Have more chicken and less pizza at dinner.” I didn’t know if he would follow through with these simple suggestions. “And get some lab work done” I urged him again. About a month later I got a phone call. “You would never believe what happened”, it was my carbo-loving male client. “I finally got some lab work done - and it turned out, my iron stores are low!” The news caught me by surprise. As a rule, low iron status is occurs more frequently in females. But looking back, there had been clues. The first one? Performance. How Does Iron Affect Performance? Iron is a very important mineral for endurance athletes. It acts like a sports car for oxygen transport, zooming it around the vascular highway. Because of its unique makeup, iron can bind up oxygen into the protein hemoglobin, which is stored in red blood cells. Once the red blood cells carry the oxygen to a cell that needs it for energy metabolism, the iron then releases it. When iron stores are severely depleted, the body is unable to produce red blood cells, and a condition called anemia results. Most of the symptoms of anemia are caused by a lack of available oxygen. They’re very similar to what a Midwesterner experiences in the mountains: shortness of breath, fatigue, faster build-up of lactic acid, and heart palpitations. In fact, if you’re wondering if you could possibly have iron deficiency ask yourself this question: am I getting out of breath doing an activity that I could previously tolerate at the same intensity, but without shortness of breath? The effects of reduced iron stores, but not totally depleted stores may be more subtle. In fact, at low intensities, you may not notice a difference. But researchers have found that women whose iron stores were low had about a 5 percent reduction in endurance capacity compared women with normal iron stores. How low is “low”? A good question, one which there doesn’t seem to be an answer for yet. Typically the diagnosis of iron deficiency is based on values for hemoglobin, ferritin, and iron stores. Exercise does affect results, because it stimulates the expansion of blood volume which dilutes hemoglobin values. This is sometimes called “psuedoanemia”, because low hemoglobin values do not reflect a true deficiency state. Lab work is an essential clue in determining iron status, followed by an evaluation by a competent physician if low values are found. Are You On a Low Iron Diet? Popeye was wrong: spinach is not high in iron. Its prominence as an iron wonder was due to the fact that an early report mistakenly gave its iron content as 10 times the actual amount. A decimal error, perhaps? I wonder what kind of rumors Y2K will start? Unfortunately, although they have many other good qualities, vegetables are not good sources of iron. Oh, the tables may list broccoli and green peas as sources of iron, but the high fiber content of these foods greatly decreases the amount of iron available for absorption. The same is true for soybeans and other legumes. This is one reason why vegetarians so often do develop deficient iron stores. Other foods can decrease iron absorption as well. Tea, which contains tannins, reduces absorption. And if you’re a coffee drinker - sorry, caffiene is just as bad. Milk isn’t the greatest choice, either, since calcium competes with iron for absorption sites in the intestine. Now that you’re totally frustrated, I do have some positive choices. The best way to enhance iron absorption is to drink orange juice, or any high vitamin C enriched beverage. This is because the citric acid changes the iron from ferric iron to ferrous iron, which is the form that the body is able to absorb. In fact, the addition of vitamin C to any meal will increase the absorption of the iron present in the food. Meat eaters will love what I have to say next: the best available source of iron is red meat. Not only is the content of iron high in beef and pork, it is in the form with the highest bioavailability. That is, you can absorb it. This form is called “heme” iron, which is a ferrous iron. Even small amounts of meat in a dish will improve the absorption of iron from other foods such as pasta. If you just can’t stomach red meat, try chicken, or fish as alternate sources for heme iron. In the U.S., most white flour, and many cereals are fortified by iron. But the fortification is largely ferric iron, not a form that has a high bioavailability. In fact, without the presence of an acid (like vitamin C), or some heme iron, not much of it is absorbed. If you’re a coffee loving, cookie splurging, vegetarian that is doing a lot of competitive running, then you may want to consider using supplements to boost your iron intake. How much should you take? That depends. Read on. Going The Supplement Route When a survey was done of the 1992 Winter Olympic athletes, 23% of men, and 47% of women had suboptimal iron stores. The highest incidence was found in Nordic skiers, the lowest in hockey players. Other data collected by the Gatorade Science Institute on 283 marathon runners found gastrointestinal bleeding (a common cause of iron loss in runners) in up to 11 percent of runners before the race. Afterwards, bleeding was present in 13 to 30 percent of runners. So if you’re doing a lot of running, why not pop an iron supplement “just in case”? Well, there is some research that suggests that iron overload can increase free radical damage, and actually raise oxidative stress. Increased oxidative stress is associated with damage to proteins and cell membranes. Although it is not proven, some researchers have speculated that increased oxidative stress can lead to a higher incidence of heart attacks and cancer. The safest way to recommend iron supplementation is to take a very individualized approach. Could you have high iron losses due to occult (hidden) gastrointestinal bleeding associated with running? Does your diet contain heme sources of iron at least three times per week? If you suspect iron deficiency, get your iron, ferritin and hemoglobin levels checked by a physician. In non-anemic athletes with suboptimal iron stores, the current recommendation to avoid further depletion is to supplement with up to 50 mg of ferrous iron per day. Doses above 50 mg may be more harmful than helpful. In cases of true anemia caused by iron deficiency, 180 mg per day of ferrous iron in divided doses of 60 mg, three times per day should be taken. To maximize absorption, always take iron on a empty stomach, and down it with orange juice. Then be patient. Repletion of iron stores is a slow process, often taking six months or longer. Obviously, not all fatigue is caused by iron deficiency. And not all vegetarians develop anemia. Nor am I against eating spinach. But iron losses can be higher during periods of intense training, especially for runners. When in doubt, get checked out. As my male client told me “it’s nice not to feel bad about eating a burger once in a while”. For a smart training diet, just follow the rules of a good training program: balance and variety. Services offered by Endurance Sports Nutrition
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