Friday, November 11, 2011

All ironed out?

I've done a little research on iron deficiency and am quite surprised by some of the studies that have been performed. Most interesting is the focus on plain and simple iron deficiency regardless of Hb status. Even more curious is the potential difficulty in getting a true assessment of tissue iron levels. This is not unlike some of the difficulties faced with accurately assessing intracellular ions, such as potassium and magnesium. As Ewen suggested, it is possible that this low iron thing has been around for a while. My last series of lab tests showed borderline ferritin levels (at the bottom of the range, but still deemed 'normal'). This may of in fact been an indication of poor tissue levels, since there aren't any readily available (outside of research) tests for measuring tissue levels. Inadequate tissue iron can impact on performance, most prominently in those that do endurance type endeavours. Now hasn't that been my main problem!? If you are interested in a bit of research. See: Tissue iron deficiency without anemia impairs adaptation in endurance capacity after aerobic training in previously untrained women. Thomas Brownlie IV, Virginia Utermohlen, Pamela S Hinton, and Jere D Haas. Am J Clin Nutr 2004;79:437–43. This article is freely available at the journal website.

As per my previous post, I will continue to supplement iron for a bit longer and then head back in for some follow up tests. I still have the mystery of why I am iron deficient in the first place. It could well be related to poor absorption given the diet is pretty good. Doing this follow up test should help give an indication of absorption capacity.

In the meantime, training has been okay this week.
Tues - Day off, friend visiting, ran out of time and couldn't squeeze in run
Wed - Gentle 6K run @ Stromlo @~5:35/K pace
Thurs - ACTVAC track - 3000m - knocked another 6 seconds off this season's best time - 13:12; 5 lap spiral 9:27 and way back in the placings this week!
Fri - an easy 5K

Track wasn't at all cruisy this week, but glad to see a few more seconds coming off that 3000m time. I  live in hope that improved tissue iron levels will help boost performance back to 2009/10 levels so I can then work on beating some of those old times! I'd prefer to be struggling to beat 12 min rather than the current 13 min battle!

6 comments:

  1. I've been reading Camille Herron's page on iron supplementation. Amazing that she suddenly started running a string of PBs after getting her ferritin levels up. She also has a link to a study on iron supplementation with athletes.

    My haemoglobin level has varied between 130 g/L and 140. I'm wondering if it could be on the low side at the moment. Agree that struggling to break 12 would be much more fun!

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  2. I just did a quick physiology review as I was wondering about the recycling of iron after haemolysis. One doesn't lose iron with haemolysis, it is recycled. For iron to get low, it needs to be due to blood loss or some minor losses through sweat and sloughing of mucosal cells. It may well go back to my over use of anti-inflams or a possible issue with iron malabsorption.

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  3. Interesting. I'm guessing there'd be a good individual variance with absorption (and loss). Vegetarians would find it harder too. I'm going to supplement for a while and get stuck into the read meat, although I think my variable form is more likely due to unbalanced training and/or simple tiredness from poor sleep habits and working hours.

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  4. Yes ET, there would likely be lots of variation amongst individuals. Still, looking at various reference sources, odds are that most of us runners need to keep an eye on our iron levels. I'm not feeling much change at this stage after 1 month of iron tablets. I have just raced out and bought liquid iron as the various reference sources suggest it is the best way to go. Watch this space :o).

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  5. Hi Janene, I found your website and post. From what I shared with you, it appears that iron is recycled when the body is in a "normal state". However, when under a lot of stress, such as with heavy training, it's excreted (fecal? Urine?). This is evident by the low iron stores seen in most distance runners.

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  6. Oh yeah, I'd suggest supplementing with B12 along with the iron.

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