Guest guest Posted July 2, 2005 Report Share Posted July 2, 2005 Hi Gay, I thought I'd take a stab at question #2. First, I think that you are defining MHR incorrectly. How are you measuring this? Is this simply the highest reading you're getting on a pulse rate monitor during exercise? A person's MHR doesn't vary day-to-day or week-to-week like you're describing. It has nothing to do with fitness or ability. It's more a function of genetics and cardiac efficiency. Thus, one Olympic athlete can have an MHR of 220 while another can have one at 170. It has to be measured in a series of stress tests that continue to push your heart until it reaches theoretical limit. The shape of the HR curve is logarithmic and levels off at some maximum value. You aren't likely to reach it, though you may get near it. For instance, mine has been measured (professionally) at 183, but the highest pulse rate I've ever seen has been 178 when I was in a race and someone was coming up behind me fast, or whenever I ride my bike up a mountain road. Your resting HR, though, depends on your level of fitness. Usually the lower it is, the better, as you describe. Runners and other very fit people usually have low RHR. VO2 Max is your maximum rate of oxygen consumption. Sedentary values of VO2 max are genetically determined, but you can improve VO2 by getting fitter. You cannot improve MHR by getting fitter. To calculate VO2 max, your pulse rate monitor uses the maximum HR you reached during the exercise (but it is not MHR, which is a fixed value). And as you get fitter, this HR will decline for the same level of physical output. So, it is not surprising that this number increased for you recently. It means you are a little less in shape than you were previously when the number was lower. Diane --- In , " Gay e " <@s...> wrote: > I am hoping some of you may be more well versed on the subject of > HRM and VO2Max than I am and can help me out by answering a couple > of questions. I think the topic of short duration exercise is > relevant to CRON. > > I have always taken a very slow, build up, type of approach to > exercise because I have CFS. Lately I have been able to do some > interval work on my elliptical, after a short warm-up, which seems > to be beneficial and certainly doesn't harm me. > > I have been reading about the theory than long duration exercise is > pointless for protecting the heart (can it really be true that it > makes it smaller?) and that it does nothing for the situations where > the heart beats faster eg running for a bus. This made sense to me > as you wouldn't warm up in this scenario, just take your heart rate > up fast. The theory is that 10 minutes a day is all that is > required to train your heart this way although the `program' begins > at 20 minutes at a lesser exertion rate. > > Even though it advocates training up to it using a perceived > exertion level of 1-10 and starting at 2 the first week, it still > means raising your heart rate quickly rather than a warm up. This > goes against everything I have been taught previously as regardless > the possibility of pulling muscles etc. (I did some stretching > before I started btw, not that this was suggested). > > To cut a long story short, for me personally, it was a disaster. > The lack of a warm up was detrimental to my illness. No permanent > damage done but I won't be trying it that way again. So here's my > questions. > > 1. Although I can see a case for getting the heart used to a > rapid increase in rate, what about the lack of a warm up? > > My second question is about VO2Max which my polar monitor records > for me. I have a very loose understanding of VO2Max but my figures > this morning surprised me. My VO2max 2 weeks ago was 37 and my Max > HR 173. Previously both have increased or decreased together. They > have been at this level for about 2-3 months without moving at all. > > With a potential crash with CFS comes excessive calorie burning and > an increased resting pulse. I checked my figures to see how my body > was reacting to the exercise I attempted on Monday; I had been > tired Wednesday and Thursday and did half my usual swim Friday, > possibly a mistake. > > My resting heart rate was up from about high 50's to high 60's and > my VO2Max was down from 37 to 36, both of which I expected. However > my MHR was up from 173 to 175, an all time high. This really > surprised me as it has always gone down in the past when my VO2Max > went down and by all accounts I was expecting it to be about 170 > perhaps less. So: > > 2. Does anyone understand VO2Max and Max Heart Rate > calculations well enough to explain this phenomena to me, in > particular the relationship between the two? > > Sorry if this sounds a bit pedantic. I know most of you won't > understand the mechanics of CFS, nor would I expect you to comment > on that but it's really important that I try and understand what's > happening on the exercise front. I can't attempt CRON until I can > stop excessive calorie burning. I won't be raising my heart rate so > quickly again, for a while if at all, so this is my only opportunity > to try and guess/understand if this strengthened my heart (or would > have done had I continued). > > Many thanks Gay Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 2, 2005 Report Share Posted July 2, 2005 In answering question #1, I haven't found any study that suggests that long duration exercise is pointless for protecting the heart. Can you forward a reference for this conclusion? What I've read (all over the internet) is that *all* exercise is good for the heart. The more the better- low or high intensity. Any exercise helps lower LDL, but high intensity is better at raising HDL -though I haven't yet found the mechanism described for why that is. High intensity exercise gives more opportunity for injury, particularly if you don't warm up. I don't understand that philosophy at all. You *absolutely* should warm up. Why would warming up reduce benefits of subsequent high intensity exercise? I'd be very interested in seeing the source of this philosophy. Diane --- In , " Gay e " <@s...> wrote: > I am hoping some of you may be more well versed on the subject of > HRM and VO2Max than I am and can help me out by answering a couple > of questions. I think the topic of short duration exercise is > relevant to CRON. > > I have always taken a very slow, build up, type of approach to > exercise because I have CFS. Lately I have been able to do some > interval work on my elliptical, after a short warm-up, which seems > to be beneficial and certainly doesn't harm me. > > I have been reading about the theory than long duration exercise is > pointless for protecting the heart (can it really be true that it > makes it smaller?) and that it does nothing for the situations where > the heart beats faster eg running for a bus. This made sense to me > as you wouldn't warm up in this scenario, just take your heart rate > up fast. The theory is that 10 minutes a day is all that is > required to train your heart this way although the `program' begins > at 20 minutes at a lesser exertion rate. > > Even though it advocates training up to it using a perceived > exertion level of 1-10 and starting at 2 the first week, it still > means raising your heart rate quickly rather than a warm up. This > goes against everything I have been taught previously as regardless > the possibility of pulling muscles etc. (I did some stretching > before I started btw, not that this was suggested). > > To cut a long story short, for me personally, it was a disaster. > The lack of a warm up was detrimental to my illness. No permanent > damage done but I won't be trying it that way again. So here's my > questions. > > 1. Although I can see a case for getting the heart used to a > rapid increase in rate, what about the lack of a warm up? > > My second question is about VO2Max which my polar monitor records > for me. I have a very loose understanding of VO2Max but my figures > this morning surprised me. My VO2max 2 weeks ago was 37 and my Max > HR 173. Previously both have increased or decreased together. They > have been at this level for about 2-3 months without moving at all. > > With a potential crash with CFS comes excessive calorie burning and > an increased resting pulse. I checked my figures to see how my body > was reacting to the exercise I attempted on Monday; I had been > tired Wednesday and Thursday and did half my usual swim Friday, > possibly a mistake. > > My resting heart rate was up from about high 50's to high 60's and > my VO2Max was down from 37 to 36, both of which I expected. However > my MHR was up from 173 to 175, an all time high. This really > surprised me as it has always gone down in the past when my VO2Max > went down and by all accounts I was expecting it to be about 170 > perhaps less. So: > > 2. Does anyone understand VO2Max and Max Heart Rate > calculations well enough to explain this phenomena to me, in > particular the relationship between the two? > > Sorry if this sounds a bit pedantic. I know most of you won't > understand the mechanics of CFS, nor would I expect you to comment > on that but it's really important that I try and understand what's > happening on the exercise front. I can't attempt CRON until I can > stop excessive calorie burning. I won't be raising my heart rate so > quickly again, for a while if at all, so this is my only opportunity > to try and guess/understand if this strengthened my heart (or would > have done had I continued). > > Many thanks Gay Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 2, 2005 Report Share Posted July 2, 2005 Hi Diane - thanks for your comments. I'm confused about the Max HR on my Polar Monitor now. I think it must be their own version of MHR and mine definitely does change. It used to be lower but has stayed at 173 for a while and now increased a little. Their words: " The HRmax-p definition is carried out simultaneously with the Polar Fitness Test. The HRmax-p score predicts your individual maximum heart rate value more accurately than the age-based formula (220 minus age). " I'm uncertain of the relevance of this figure now. I am 53 so the 220-age would give 167. I recall the Polar figure from my monitors Fitness Test gave less than that when I first had it. The VO2Max I can understand a little better. What threw me was why my VO2max went down and my HRM went up. Perhaps I should ask Polar the question. I have been reading two books and discussing them with a friend. Al Sears `The Doctors Heart Cure " and a book I read ages ago (and ignored at the time), " Total Fitness in 60 minutes per week " by Morehouse and Gross. My friend recently bought both books. I read a lot and discard a lot too <grin> In this case, I can see where it's heading and why but I'm not sure I like the approach. Whilst I can understand the theory behind interval training and the idea also, per Sears, that you can gradually train your heart to respond quickly to various levels of exertion, his `Full Tilt Program' at week 8 (for 10 minutes) begins with 1 minute at intensity level 5 (perceived range 1-10). Past the start it is not so different from other interval training and HITT stuff I've read. I already do some interval training, for more than one reason, but the idea of not warming up seems a bit crazy. I can see that - perhaps- it may offer protection in the long run but what about the risks every time you start cold? Sears says `long duration exercise is a waste of time'. I won't quote all the detail as I wouldn't want it to sound as if I was attempting to follow all his logic. He actually states that long duration exercise forces the heart to become smaller. I have no idea whether this is true or not. The gist is that it does not protect against `sudden sizeable demands'. There are references at the back of the book but short of reading the whole lot ……. BTW, Sears also states that interval training lowers cholesterol AND improves the ratio. Regards, Gay > In answering question #1, I haven't found any study that suggests that > long duration exercise is pointless for protecting the heart. Can you > forward a reference for this conclusion? Quote Link to comment Share on other sites More sharing options...
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