A little while ago, I posted a quick podcast on the role of carbohydrate and overtraining. When training hard by volume, intensity, or both, the lack of carbohydrates has a direct relationship with performance (and mood). The reason I discussed that idea was to try to show people how the idea of overtraining is confused with the idea of cumulative fatigue in marathon training. The problem is, it’s like when your check engine light comes on and the mechanic gives you a range of options from the gas cap not being tight all the way to catastrophic engine failure. There are those two possibilities and about 5 more in between the extremes. Fatigue can be quite the rabbit hole to dive into. However, dive we must, and hopefully, with a few posts, we can cover a lot of the areas we can look at first. Maybe we can avoid catastrophic engine failure.
Most of us are aware of iron and its importance for performance. However, for sake of making sure, iron is a mineral that is crucial for energy metabolism (processing carbohydrates), transporting oxygen, and the acid-base balance in the body. Being deficient can result in weakness, general fatigue, a higher heart rate, shortness of breath, and your performance. The worst part is that endurance athletes can lose iron 70% more than their sedentary counterparts! We lose through heavy sweating, our urine and GI tract, and the mechanical force of our feet crashing into the ground at 180 +/- steps per minute. Women also lose iron through their menstrual cycle. Oh, I forgot to mention- iron doesn’t really absorb that well either.
Before you decide to leave your car on the side of the road and walk it home, let’s finish this out. We can run those diagnostics and get you back on track!
So, to switch away from the silly car analogy, let’s talk about iron stores. It’s kinda like a pantry and your kitchen. You have the stuff you use every day that’s in your cupboards and fridge, but you may also have bulk items stored that fill the backstock. We use our day to day goods. We eat our cereal and cook our hamburger. We get low and take another bag out from the four in the pantry and another pound of burger from the bulk we bought at Costco. Things are all good, right? The problem is, we haven’t been back to Costco in two months and we haven’t been replenishing the long-term storage. So, right now, our day to day is fine because we are pulling from the reserves, but the reserves will only last so long. Iron Deficiency works a bit in the same way. We have iron stored in a blood protein called ferritin. We are training hard, sweating profusely and feet just slapping away at the concrete. No problem though, we’ll just pull from the ferritin. Uh oh, I haven’t been refilling the pantry as fast as I’ve been taking it out. Now we are starting to get into trouble. So, let’s look at the three levels of iron deficiency.
This is a diminished total body iron content and can be determined by looking at your serum ferritin. Performance may not be affected yet, if the ferritin in the liver is only diminished. Once the muscles have been impacted, then you’ll start to see performance start to drop. This is where we have the pantry and are using the iron here to satisfy needs in other places in the body. (Form red blood cells that we are breaking down)
To be in this state, you are looking at a serum ferritin level of less than 35 ug/L (micrograms/Liter). Hemoglobin and transferrin saturation will still be normal at 115 g/L and above 16, respectively. Honestly, though, a lot of runners don’t feel “spunky” after their levels drop below 50. So, knowing your trends is good. Also, the low end of “normal” is 15 for both men and women. I have had women completely exhausted, get blood work, and have the doc say it looks ok, still normal. I look at it and their ferritin is at 15 or 16! So, make sure you have someone read it that understands athletes. Personally, I get mine done and take it to my chiropractor. He knows where I should be after years of treating me. This is compounded that ferritin levels can rise quickly due to stress, inflammation, and infection, which would give us numbers that are falsely inflated. Go figure!
At this point the cupboards are sparse. Ham and cheese sandwiches have become grilled cheese sandwiches. When we are at this point, ferritin stores are getting to the point where they can no longer support the full production of red blood cells. You are still making them, but capacity has been reduced. To compensate your body will try to use zinc to make up for the iron that is not readily available. If we are in this stage, ferritin will drop below 20, hemoglobin will still be normal, but another blood protein that carries iron, transferrin will be less than 15% saturated. This means that less than 15% of the protein is carrying iron.
Now we are at the point where there’s nothing in the cupboards or the fridge. When we get to this stage, hemoglobin is affected. Hemoglobin is the protein that carries oxygen from the lungs to the tissues, while bringing carbon dioxide back to the lungs. If we get to this point, everything will be lower. Ferritin will be less than 12, transferrin saturation will be below 16, and hemoglobin will be less than 115. If you are at this point, training is going to be pretty darn tough to maintain. Performance will be significantly down. I’d be surprised if you were running anything of any substance.
Improving the situation
We have already mentioned that there’s problems with keeping iron levels up and training hard. We break it down at much faster rates than average people and the bioavailability of iron is less than ideal, much less. You have two types of iron- heme and non-heme. Heme iron is more readily available and better absorbed than non-heme iron, about 40% compared to 5%. Yes, you read that right. Heme iron is found mostly in animal sources, while non-heme is nearly 100% non-heme. Now, non-heme iron is absorbed better when in the presence of heme iron, but you get the point. It’s not easy to get iron from the stomach to the bloodstream.
Time your iron intake properly. Another reason to make sure you are getting your recovery food in. A meal with iron in it (or supplement) along with a glass juice within 30-60 minutes of exercise improved absorption of iron. It’s also important to note that absorption is better in the morning, too. So, regardless of running, this should be done in the morning. Foods like eggs, bacon, sausage, peanut butter are all higher sources, along with chicken, spinach, and broccoli. On the flipside, milk and coffee reduce absorption significantly.
Oral supplements. Working with a sports physician is key here for optimal dosage, but I know many of you take an iron supplement. If you do, a slow-release ferrous sulfate is your best bet. Now, taking every day can create GI issues. Taking with the OJ definitely helps, but absorption between taking once a day and taking every other day didn’t impact absorption significantly but did reduce GI symptoms. There are patches available, too. However, it seems that the absorption rate of these are less than that of oral supplements. But, these are pretty new and improvements are constantly made. These may be a more viable option in the future.
IV is all the rage, right now, so why not get an IV? No, don’t! I am kidding. I don’t think you can just get these at the IV shop, anyway. Now, these work with a 100% absorption rate, but you HAVE to work with a physician. Over the years, I have seen some physicians adamant that a person only gets severe problems. However, these have mostly been family physicians that don’t work with athletes. I have seen many sports docs offer it up if the blood work indicated it was necessary. I will say, I have had athletes with ferritin in the 10-15 range and just miserable. They got an IV and set PR’s within a couple weeks. But, it is key to work with a sports physician on this. If you go this route, get blood tested a month later and then again at 6 months after to see what your ferritin is doing.
If you are starting to feel the tiredness, the fatigue, and most importantly, a loss in performance, then something isn’t right.
The first thing I’d look at is your carbohydrate intake. It’s simple to do and it’s non-invasive. Maybe at the same time, you get your blood work done. I know it’s a pain to get a doctor’s order and then go to the blood draw. There are other options now, too. Companies like Inside Tracker and others allow you to streamline this process. Now that you have numbers that are for runners, you are armed with info. If your general practitioner says you are fine, but your ferritin is at 25, you know better. Find a sports doc or a physician that works with runners (or is one). Time your iron at the right time while working with said doc to make a plan for supplementation. My biggest piece of advice- don’t let it get past phase two. Don’t let it go for months. If you are 6 weeks in a plan, tired, and slowing down, let’s figure it out. We can still save the segment.