The 12th Invest in ME Conference, Part 1
OverTheHills presents the first article in a series of three about the recent 12th Invest In ME international Conference (IIMEC12) in London.
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Questions about Anaerobic Threshold and Exercise

Discussion in 'Post-Exertional Malaise, Fatigue, and Crashes' started by JayBO, Mar 8, 2015.

  1. JayBO

    JayBO

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    Hi, I want to use a heart rate monitor in order to avoid PEM, but after doing a lot of reading about the anaerobic threshold (AT) and energy pathways, I'm still a little confused as to some of the the mechanisms involved with fatigue and PEM.

    Here is my understanding, please help me to understand this better:

    PEM is triggered when the heart rate reaches near or above the AT (for a certain duration).

    AT is significantly lower in CFS sufferers than in others (aprox. 60% max heart rate).

    So here are my questions:
    Is the point of using a heart rate monitor to prevent anaerobic energy production...?
    Does keeping heart rate under AT mean that the activity is aerobic and less likely to cause PEM...?
    So is PEM caused by anaerobic or aerobic exercise...?
    How does this relate to fast resting heart rate during PEM crashes (or in general)...?

    I'm sure I have more questions but I will start here. Thanks for any information and clarifications!
     
  2. Aurator

    Aurator Senior Member

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    I don't know what the evidence is for PEM being triggered when we reach or exceed our AT. My own experience and that of others I know is that reaching the AT is certainly not a necessary precondition for PEM to occur.

    If you were to ask me which would be more taxing and likely to produce PEM, an hour spent in my aerobic zone at 145 bpm or 1 minute in my anaerobic at 170 bpm, I'd say the former. In other words duration is a factor, not just intensity. Staying within your aerobic zone even for short periods is no guarantee of avoidance of PEM anyway, not least because PEM can be induced by psychological stress as well as physical.

    Elevated resting heart rate during crashes is entirely consistent with being in a post-exertional state. Healthy people have elevated resting heart rate for hours, and sometimes days, after sustained exertion. Monitoring resting heart rate on waking is one of the indicators athletes use to gauge their recovery from the previous day's or days' activities. Ignoring changes in resting heart rate for a prolonged period and continuing to train and race through them is associated with the condition known as "over-training", and ultimately with something far worse.
     
    Last edited: Mar 8, 2015
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  3. Amaya2014

    Amaya2014 Senior Member

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    Hi @JayBO. I also find PEM to be complicated. I'm a year into being ill and trying to learn my limitations. A week ago I was triggered into PEM by live music that was too loud for me. Weather changes, especially foggy, humid days, are triggers. Even too much emotional stimulation (very bad news or intense sexual excitement) can be potential triggers.

    Not to be a Debbie downer, though, but avoiding PEM is not as simple as just staying under your AT. I found that knowing my AT and using the HR monitor helps me see that activity that I used to do without a second thought now impacts me differently. I'm more aware of my limitations and try to listen to my body. So, the point of staying out of anearobic for me is to maximize what I am able to accomplish and HOPEFULLY minimize crashes.

    I'm currently able to engage in low impact aerobics and can tolerate about 20mins of aquatic therapy (if I stick to walking and basic stretches in the pool). But even this is dependent on what else is going on in my life, the weather, etc.

    I'm not sure about the resting heart rate stuff. Hope I could help some. I'm curious myself how others are using supplements, diet, and/or other techniques in order to include exercise within their disease management.
     
  4. JayBO

    JayBO

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    @Amaya2014, I agree with what you say. In fact I think the heart rate monitor will help me not only with exercise but with my general limitations as well. In fact this weekend I'm experiencing a minor crash. Its very frustrating because I have not exercised lately but this has been a long week and stressful for a variety of reasons, and was hoping for this weekend to exercise a little bit but discouraged to find rapid heart rate and fatigue (resulting in a lot of bed rest). Probably cumulative effect from doing a lot during the week. My exercise is so little, maybe 10 minutes on exercise bike at very low intensity, but I know that would only make my symptoms worse right now, very frustrating.

    In any case I've been dealing with this for many years and learned to pace myself to the point where crashes are less frequent, but I must be content do so much less than I would like (at work, at home, socialization, etc). Crashes with no specific trigger are the most frustrating. Years ago I recognized that if my heart rate rises above a certain point, I become over heated and are more likely to get PEM. I now see that this point is about the same as many others who discuss the AT threshold, about 110 bpm. If the resting heart rate is higher and the anaerobic threshold is lower, there is a small window within which we can exercise. I even experimented with cool showers after exercise to dissipate core body heat, but that was not effective in staving off PEM. And this is LIGHT exercise unfortunately.

    @Aurator, my understanding is that everyone must use energy not exceeding a rate in which the body can supply it (demand can not be higher than supply). If there are fundamental problems with energy supply as in CFS (on a cellular, mitochondrial level I believe), then producing energy faster then the ability to recycle new ATP (for whatever reason) results in a switch to anaerobic cell respiration (at much lower heart rate) and a depletion of raw materials used to produce energy (PEM), taking days/weeks to produce from scratch depending on level of disability. The move to anaerobic respiration occurs more quickly because of the cell's inability to sustain aerobic respiration (and/or greater need for fast-twitch muscle contractions), and indicates depletion of mitochondrial raw materials.

    Personally I would ust like to engage in very light cardio that does not result in PEM, however I am fortunate enough to work full time and am usually depleted by the end of a work day (and even moreso at the end of the week) making any exercise nearly impossible. I just want to understand this process better so I can design a way to keep myself from losing all fitness, and maybe gain some.

    Again that's my understanding without any background in biology. I'm just trying to problem solve, however there are many variables and the problem is not entirely defined.

    Question: For those able to engage in light cardio, how do you prevent PEM, and do you see benefits from a low level of exercise? Thanks
     
  5. Aurator

    Aurator Senior Member

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    Unless you have an extremely sedentary and unstressful job (if so, lucky you!), I'm astonished that you can work full time and yet "any exercise is nearly impossible". For someone physically up to working full time in the first place, ten minutes of gentle aerobic activity on a static bike, for example, would seem to me a far less formidable feat, from a PEM standpoint, than a whole day spent working. In fact it would seem to me a less formidable feat than just driving to work is for a lot of people.

    I could be wrong but it sounds like it may be your full-time work that is causing your PEM, not the very limited amount of gentle exercise you are doing.
     
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  6. JayBO

    JayBO

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    I don't remember the last time I attempted the light exercise or felt up to it, which is why I want to find a way to be better in control of the symptoms, or at least be able to measure my levels of exertion better to that end. Yes, the job definitely takes a lot out of me. If I pace myself as much as possible I can mostly avoid PEM, but I spend many weekends catching up on sleep and taking it easy. Its mostly the paperwork part of my work that gets me into trouble as I have difficulty focusing and my eyes fatigue quickly. Unfortunately, as a result of this condition my baseline level of energy is low, and its impossible to function without using up my energy reserves on a regular basis. And while I've never been in great shape, I feel the results of almost two decades of sedentary living are taking their toll. It took many years just to learn how to take care of myself and be attuned to the way my body feels, and that I think has allowed me to conserve my energy enough to hold down my job, but it's a struggle.

    In any case, I'd like to exercise, even just a bit, on a regular basis. It would make me feel like a real person. I'm determined to see if there's any way I can do so without feeling worse or exacerbating symptoms. Any advice appreciated. Thanks.
     
  7. Sushi

    Sushi Moderator and Senior Member Albuquerque

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    I lived like this for years so know what it is like. But I'd like to add a caution from my own experience: I was tipped into full disability by overdoing. Once that happens, it is very hard to regain lost ground. Circumstances more or less demanded that I exceed my energy envelope, but it had huge consequences. I think others have had this experience too.

    I understand your desire to exercise a bit. I had that too, but when I tried it, I got PEM, though I didn't have a name for it then.

    Sushi
     
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  8. JayBO

    JayBO

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    @Sushi, thanks for the advice. I spent my twenties periodically pushing myself to do more, and then crashing for weeks not knowing how long it would take or if I would ever feel better, a miserable experience. Its been a slow process but I've accepted my limitations to a large extent and understand the need to go very slow. I just hate feeling like I only have the amount of energy to function at this level and no more. I've seen some doctors with nominal benefit. I'm a realist, not expecting a cure. I understand there is a chance that any exercise will disrupt this delicate equilibrium, but I'm willing to go very slow and stop at the first sign its too much. And I'm not going to start exercising during periods of fatigue no matter how much I'd like to. Just looking for some advice from people who are able to engage in light exercise, or who try, such as types of exercise, ways to measure exertion, etc. Believe me, I'm not about to start exercising like a madman.
     
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  9. Sushi

    Sushi Moderator and Senior Member Albuquerque

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    I am now able to do pilates with machines. (once a week). This is done mostly lying down. I use a heart rate monitor to judge if I am overdoing. This works pretty well for me.

    Sushi
     
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  10. helen41

    helen41 Senior Member

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    I had my VO2 max done, and was advised not to allow my heart rate to go above 113. At the same time, they said that walking at a normal pace, whatever my HR, would deplete my energy and was not sustainable.
    I understand the HR measure as just one more indication of when I am overdoing things. I try to stay under that, but exceed it many times a day, and I don't crash. On the other hand, if I sit up in a car for a couple of hours, I will feel horrible, even though my heart rate never exceeded my max.
    I believe it is just one more tool. Noise, concentration and light all impact me as well.
     
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  11. Amaya2014

    Amaya2014 Senior Member

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    I wanted to clarify that I haven't been working. Probably the only reason I can engage in some exercise is because I spend most of the rest of time recovering from these sessions. I agree with @Sushi that it's wiser to be very cautious on how we expend energy.
     
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  12. helen41

    helen41 Senior Member

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  13. Sherlock

    Sherlock tart cherry etc. for joints, insomnia

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    Czechosherlockia, USA
  14. JayBO

    JayBO

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    @Sherlock, Thanks for linking the baking soda thread. As it's 19 pages it will take me some time to go through it and see if there is anything I can use.

    @helen41, the thread describing your VO2max testing is very informative too and clarifies for me some of the science behind AT and relationship to PEM, thanks!
     
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