Effect of Anemia on AeT/AnT

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  • #22339

    Hi there

    I am a 37 year old female and am currently doing the 20 week Intro to Ultra Running training plan. I’ve been running for 5+ years but have only been running longer distances (up to 30km) the last two years.

    I had a severe anemia up until two years ago, and am wondering if this has affected my AeT/AnT. My hemoglobin was 82 (8.2 in the US) and my ferritin was 2 when I was diagnosed. This was corrected after 3 rounds of iron infusions. I was running very very slowly during this time and could not run for more than an hour, and when it was at its worst I could barely run a mile. I think this had been going on for 2-3years and I just attributed it to fatigue/sleep deprivation/being out of shape.

    I’ve done the AeT an AnT as described in the plan. I’ve done the heart rate drift test a few times and the nose-breathing treadmill test for AeT.

    My AeT is surprisingly high – I got 169 using the heart rate drift test on a flat loop. This is similar to what I got using the nose breathing test. My pace is slow though-I covered 9km (5.6 miles) in the 1h test on a flat gravel path.

    My AnT is ~183.

    Just curious if you have any thoughts on how anemia can affect AeT/AnT and if these effects can persist even after the anemia is corrected? I’m a physician and have given this some thought – I can see how my AnT would change since my cells were probably so oxygen deprived with exercise but have a harder time understanding how this would affect my AeT long term – unless my cells just adapted to being more efficient at using oxygen and that persisted even after the anemia was corrected…

    Also-given my results (if they are correct) i.e. high AeT, but slow pace, do you have any advice on modifying the training?

    I included screen shots of the training peaks data in case I’m interpreting it wrong…

    Thanks for your help!

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    Anonymous on #22380


    I have some experience dealing with young women athletes who were anemic and with low ferritin. I’ve never seen such low numbers before however. No doubt your were massively impacted by that during those years. How that will affect you years later I can’t say. You do not say what your current numbers are. But…..I have seen repeatedly that ferritin below 30 and the athlete is pretty worthless in terms of reaching her performance potential. Ferritin below 50 will still result in performance degradation however.

    If you are just re-entering training regular running then that pace does not seem so slow for aerobic base work. I recommend you continue to train below 169 exclusively for a few more weeks and retest AeT and see if it has improved (both in pace and HR). Continue to monitor blood iron markers.


    Jo on #22432

    Great, that’s helpful. Thanks for the input.

    My ferritin was ~70 earlier this year and my hemoglobin was around 130-140 (13-14 US)…it’s good to know that a ferritin <50 would be considered ‘low’ for endurance training as this is definitely not what we are taught in medicine – we would consider levels <30 for women low.

    Would definitely recommend to others females (and even more so if they are vegetarian) to consider asking their physician to check their hemoglobin and ferritin periodically as it is crazy how insidiously anemia/iron deficiency can come on and how easy it is to brush off the symptoms.

    Thanks again!

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