Low HR Training


Low Heart Rate - Sometimes an indicator of not enough recovery? (Read 1084 times)

    I have now been training with a Heart Monitor for the past 8 months. It is a great feed back tool. Obviously we all know that, who are part of this group. But, one of the observations I have made is that sometimes my heart rate is unusually low on a particular run and it is hard to get it higher. I have seen some references to this phenomana on this board, but I have never really seen a good explanation for it or seen the issue addressed directly. When I first started MAF training, and during the first few months, if my heart rate was low for a particular run, I always thought that was a good thing. I read others peoples observations that after a particularly hard race, they noticed that their HR was unusually low in the days following it. I noticed that myself. I always thought that this was a good thing and a good opportunity to get some faster paced running in and still stay below MAF. But, then one day, someone posted a Hadd discussion group link. And I remember Hadd was quoted as saying that if one of his runners has an unusually low heart rate that day, he tells that runner to take it easy and does not allow that runner to do a hard workout. That was the first time I had read that having a low heart rate on a particular day, may not be a good thing, and maybe it is something to keep an eye on. Today, I tried to find more information on this phenomana by searching the web and I found this article. I thought it was interesting and gave more information about it. I did not find much else. http://www.slowtwitch.com/Training/How_much_is_too_much__387.html What prompted this was the fact that I posted my 5k race results on the "race reports" thread, and wondered about why my heart rate was lower for that 5k than usual. Now that I have done this research, I think it simply may be because I was just not recovered enough. The previous two weeks I had done a lot more higher rate heart training and probably did too much. What also prompted this was the fact that yesterday I went on a recovery run and sure enough, there was that low heart rate. I took it easy, but my average HR was 118 when it would usually be higher than that for the same pace. Because I am an older runner, and because I have not been doing it that long, I do not recover as well as I used to, and so I think this is why I have noticed this issue more with myself. One of the quotes from the article that made sense to me was that a low heart rate may be your bodies way of protecting your heart and not allowing you to push it to higher heart rates until your body is recovered enough. Another indicator of not enough recovery is a high resting heart rate. I think we all are a lot more familiear with that one. Anyway, I just thought this was an interesting topic and would be interested in other poeple's thoughts and observations.
      I don't really follow low HR training programs, but I do occasionally monitor my HR and have found this to be the case. My heart rate will be really low, but at the same time I feel sort of sluggish/like have not recovered enough and my pace is slower than normal at a given effort. I'm not criticizing low HR training by saying this, but this is exactly why I prefer running by "feel" instead of a heart rate zone. Usually your body will tell you how fast you should or can run on a given day, depending on the conditions (how refueled, hydrated, and recovered you are, the weather, etc.). A HRM is still a great tool to use if you know how to use and read it properly. Below is the post from Hadd on LetsRun.com. He basically says that it could be that you haven't recovered/refueled enough and that you should take a day or two of easy running/recovery with extra carbs. http://www.letsrun.com/forum/flat_read.php?thread=2375989 Page 1 towards the bottom:
      ... I mentioned above that I might curtail a session if I thought the runner was working harder than I wanted. Some readers might take that to mean that I am waiting to learn if the HR is higher than I would expect at that running pace. Actually the opposite is much more likely to be true; I stop the session because the HR is much lower than I expect it to be for the pace involved. This seems paradoxical. And it often appears that way to runners until I explain to them precisely what the HRM is telling them. Let’s say I expect an HR for this session in the range of 180-185. I expect it because I know the pace involved, I know what percent HRmax such a pace should require, and I may even have done the same session with this runner in the past, so I know precisely what to expect. I’m not expecting any surprises. So if the runner is coming round each lap (on pace) and calling out 176... 177... then I watch very closely. Okay, the first few times this happens to runners the coach might be excused for thinking that the runner has suddenly got much fitter. A drop in HR at the same pace is generally taken as a sign that the runner is “working less”, ie: fitter than previously. Of course that COULD be the case here, but if I also see that the runner is having to work hard to maintain pace, I stop the session. From experience we have learned that when such a situation occurs, (the HR “will not come up”) then it is because the runner has not fully refueled muscle glycogen from a previous training session, or (in some other way) has not fully recovered from previous training. I often bag the session and send the runner home with instructions to eat more carbos – maybe also just jog easy for a day or two to help refueling/recovery. When we reschedule the same session for 2-3 days later, we often find the HR is higher, but is in the expected HR zone PLUS the runner finds the pace easier to handle. So, there you are: a low HR is not always a good thing and a higher HR is not always a bad thing. A lower-than-expected HR is much more likely to be a sign that the runner is under-fuelled, or not fully recovered from previous training. Much the same as a lower-than-usual lactate value at a running pace is not always a sign of increased fitness; it might simply be a sign that the runner is low on muscle glycogen. In both cases (HR and lactate) the runner will often corroborate this by admitting the pace is “harder than usual” on that occasion. A higher-than-expected HR on a given night is NOT a sign of lack of recovery from previous training. But it can mean the runner is coming down with a cold/infection. It could also mean that he/she did not sleep well enough the previous night. If the runner is otherwise okay, the session might be completed that night, but watch their health for the next few days and get them to make an extra effort to get more sleep.
        The problem with this however is how do you ever know when you are improving or just tired..... That's why I like MAF. It just a single number (180-age). And on my easy runs, I let my HR get up to that number and not go over it. If my HR is lower, than its lower. My legs and body will tell me if I can run any faster.... I too usually get a lower HR the day after a hard workout. However, the day after a hard workout is usually a MAF, easy run so I don't see the problem in that. My HR is sometimes lower because my 1st mile is usually slower since I am stiffer from the hardwork out. However, over a general period of time you should notice you are running faster at the same HRs....
          Hi Dustin, Thanks so much for digging that up from that Hadd discussion link. I knew I came across it before, but I did not remember how well Hadd had explained it. It definitely makes sense, and I have definitely observed this low heart rate phenonoma with myself. It makes me feel a lot better to have it explained the way he explained it. That is the one good thing about MAF, you are always running at a low enough heart rate, that you are in a zone that many people call recovery runnning. But, you make a good point, in that, you also have to go by how you feel. This really helps explain a lot of things. I just remember early on that I thought I had suddenly made some big improvement in my MAF pace, when in reality, my heart rate was lower than normal for a given pace because I was recovering from a long run or a race or something. I now know that MAF improvements are very gradual and any big changes one way or another from one day to the next is usually just noise. Heart rate can vary and MAF pace can vary due to so many things.


            When I have those days, I just go with them. I see it as a train wreck between high aerobic fitness and being worn out. Just the body telling me that today should be an easy day. And sometimes, it's 3 days in a row.