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  • Fraser Cartmell: Here's a question for you, do  you monitor your resting heart rate or indeed  

  • pay attention to what your heart rate is doing  whilst you're training, in general? If you do,  

  • then are you feeling fitter if you start to see  those numbers drop over time, and especially when  

  • you're competing for sessions with each other? Or  perhaps you pay attention to what your training  

  • buddies or your friends are doing and you  find yourselves competing amongst yourselves.  

  • Should you? Does this even matter at all? Well, to answer a few of these issues and  

  • delve into the complexities of heart rate in  a little bit more detail, I reached out to  

  • a pair of experts who are going to talk to me  about what it means to have a lower heart rate,  

  • how this might indicate levels of fitness and  what other factors could influence this too.  

  • [music] In this modern age of social media and ready  

  • access to online content it's remarkably easy to  follow along with what the pro-athletes are doing,  

  • especially when some of them are so transparent  with sharing with us their online training data  

  • via their social media platforms. Nowone such athlete who is particularly  

  • happy to lay bear the nuts and bolts of  his training routine is multiple Ironman  

  • and Ironman 70.3 champion, Lionel Sanders. Now in the context of this video, that's  

  • particularly useful because those of you who pay  attention close enough will perhaps notice that  

  • Lionel has what appears to be an incredibly low  heart rate during all these incredible training  

  • sessions that he is churning out on the bike and  run. I thought I would get in touch with Lionel's  

  • coach, David Tilbury-Davis to try and delve  into this subject in a little bit more detail,  

  • Now, David has been coaching athletes  of all abilities for over 20 years now.  

  • He's also lectured in anatomy and physiology  too, added on top of his first-hand experience  

  • of coaching an athlete of Lionel's caliber. I was  keen to hear his viewpoint on what it might mean  

  • to have a lower heart rate. [music]  

  • I started by asking David if he could explain  the physiology of the heart a little bit  

  • and highlight the variances from person to  person, and also perhaps why somebody like  

  • Lionel would have such a low heart rate value. David Tilbury-Davis: First of all, there's the  

  • transportation of oxygen through the lungs into  the bloodstream, and clearly, the more that you  

  • can do that the more talented you are likely  to be as an athlete. That's why you hear of  

  • these very high oxygen kinetics numbers for Kenyan  Marathon runners. Now, once that oxygen is in the  

  • bloodstream you've then got your red blood cell  count which is carrying about 98% of the oxygen  

  • that gets absorbed, other 2% ends up in the plasma  volume. That oxygen then, gets pumped through the  

  • heart and then moved to where it's needed. In terms of the actual heart,  

  • you've got the size of the heart which is a key  factor. You've got gender differences. Typically,  

  • pound for pound, similar, weight male, femaleheight et cetera. The female will still have a  

  • physically smaller heart. Then obviously, you've  got a broad spectrum of differences between  

  • individuals. You might have somebody that hasvery large heart and somebody that has average,  

  • and somebody that has quite small. In my own personal experience,  

  • I can give you an example where I was working  with an amateur athlete who was in her 30s  

  • on a training camp with us. We were out forrun and she was explaining that her personal  

  • trainer had said her maximum heart rate was 220  minus her age. She was in her early 30s, and  

  • she was running along, chatting away to me like  we're talking now and her heart rate was 192.  

  • I explained to her, "Well, actually, geneticallyyou probably just have a very small heart and  

  • consequently, you have a very high heart  rate to achieve a certain rate of blood flow  

  • or cardiac output because cardiac output is  simply stroke volume times your heart rate."  

  • Going right back to then somebody like Lionelthen you have an individual here who clearly,  

  • in my mind, has a very large heart, not  in a medically risky way, because there  

  • are things like cardiac hypertrophy which  unfortunately happens in some athletes.  

  • One aspect of training as an athlete is you  get what's called athlete's heart, and this  

  • is the most prominent part of that athlete's  heart, is an enlargement of the left ventricle.  

  • That enlargement creates an increase in  stroke volume, which increases the delivery of  

  • oxygen to the muscles, so that's a byproduct of  endurance training. You couple that with somebody  

  • that naturally has a large heart, you're  going to have a very low resting heart rate  

  • but you're also going to have a ceiling on  the maximum heart rate because there's only  

  • so much oxygen you can transport going back  to that, what you can absorb, limitation.  

  • That's why in individuals like  Lionel, whilst you might see  

  • that when they're riding moderately hardheart rates of 120 in his early 30s,  

  • you're also not going to seemaximum heart rate of 180, 190.  

  • Fraser: Given David's example of the female  athlete with a higher heart rate, I asked him if  

  • this is a good way perhaps of proving that athlete  to athlete comparisons aren't helpful, given she  

  • could perhaps have been running alongside another  friend perhaps with a significantly lower heart  

  • rate, which of course is entirely possible. David: In the same way that there might be height  

  • differences or leg length differences or muscle  mass differences, or fiber type differences,  

  • there's also minor difference in cardiac  morphology, I guess is maybe the right word.  

  • In that scenario, I would say that  you're really best comparing heart rate  

  • reserve which is the difference between your  resting heart rate and your maximum heart rate,  

  • and then whatever you're at aspercentage of that heart rate reserve  

  • is probably the best comparable  comparison between individuals.  

  • Fraser: In addition to this notion of a wider  heart rate range, he also explained what might be  

  • an indicator of improved fitness and  he used swimming as a case in point.  

  • David: As you get fitter typically, you see  resting heart rate lower. In some instances,  

  • you either see an increase in maximum heart  rate or you're at least see a stabilization  

  • of it and you might say, "Hang onminute. Why would I see an increase  

  • in maximum heart rate?" Well, a good example is  swimming. Swimming is very technically driven.  

  • If you're an adult onset swimmer, when you start  out, your mechanical efficiency in the water is  

  • really quite low comparative to Alistair or  Jonny Brownlee. Your capacity to express  

  • force against the water is not limited by your  actual central cardiac output, it's limited by  

  • your muscle recruitment and muscle usage. As you improve in technique and you improve  

  • the ability to apply force to the wateryou're going to be placing a larger demand  

  • on the heart, so the maximum heart rate  may increase in the swim. That's a simple  

  • example of explaining why it might increase. Fraser: The crux of this is that we're talking  

  • about apples and pears. Lake simply isn't being  compared with lake. Because of all the variables  

  • at play, it just isn't helpful to form an  opinion on our level of fitness because of  

  • what our heart rate is doing compared to others. David: The simplest analogy I've always used with  

  • all these things is, if you imagine that one  is like a car then your speedometer is the  

  • power meter, is the pace that you're running  out with your Garmin or the pace in the pool.  

  • That's your speedometer. 50 kilometers an hour  is 50 kilometers an hour is 50 kilometers an  

  • hour. Your RPMs is your heart rate. Clearlyfor a 50 kilometers an hour you can have quite  

  • a variance in RPM depending on the environment  that you're driving in, all sorts of factors.  

  • Then your fuel economy is your RPE, and againthat can be influenced by various factors.  

  • When you look at that triumvir as an athlete and  you use that as your decision-making mechanism  

  • not favoring one or other part, but  actually looking at those three things  

  • if you have those three things, that  allows you to make the best decisions.  

  • [music] Fraser: Another viewpoint that I thought would  

  • be interesting would be that of a physiologist  who tests and sees athletes of all abilities on  

  • a regular basis in the laboratory environment. I  got in touch with Jonathan Robinson here at the  

  • university at Bath and asked him if it was fair  to say that individual variation is inevitable  

  • and how he sees that unfolding in the lab. Jonathan Robinson: I get a lot of people,  

  • recreational age group and even more  elite triathletes and cyclists saying,  

  • "My heart rate is much higher or much lower  than my friend's or my training partner's."  

  • We do a lot of physiological tests to create  their own personal training zones based on that.  

  • You can see people performing at similar levels  with similar say, VO 2 max scores or similar  

  • lactate turn points and things like  that. Their heart rates are quite  

  • different because they've got different ranges  I suppose. Like we've alluded to, it's always  

  • really important to look at what that heart rate  range is, where it sits at resting, where it sits  

  • when you're exercising very gently, and then how  quickly it goes up, and how high it goes up. Some  

  • people could have a really low resting heart  rate, but it only goes to 150, where someone  

  • could have a little bit higher, and they can get  up to 215. You've got those differences really.  

  • Fraser: I was keen to ask him about other factors  that might impact your heart rate and hear how  

  • they might create a lowering of the heart rate. Jonathan: Commonly, it's perceived that obviously  

  • when you go from having done very little, for  example, as you start to do more endurance  

  • training, that is going to improve the strength  of the heart, and the heart can therefore pump  

  • more effectively and more efficiently and pump  more blood round for each beat, and therefore  

  • that could reduce it. That thing is probably going  to be more in a novice athlete or new athlete or  

  • someone taking up the sport more recently. Altitude training is a good example in that's  

  • been shown to increase blood volume and plasma  volume, and the same with heat training,  

  • so that you've got more red blood cells, so you've  got more blood and more oxygen-carrying capacity,  

  • so possibly the heart doesn't need to beat  quite as quickly to supply the same amount of  

  • oxygen to the body for the same workload. Fraser: It was clear from what Jonathan  

  • was explaining that heart rate in itself  shouldn't be looked at in isolation, but  

  • I was keen to hear from him what things  we could do to monitor it and perhaps  

  • what we could use as an early warning system. Jonathan: I like the age-old monitoring waking  

  • heart rate. If people do that or resting heart  rate, you need to get a baseline. You need to know  

  • that generally your heart rate is say 60 beats  a minute when you wake or something like that,  

  • and then if you see one day it's 75, then  you think, "Hey, that's unusual." Whereas if  

  • you haven't got a baseline and you do it one  day and it's 60, and the next day it's 75,  

  • you don't know what's the unusual factor really. Fraser: Now, I really enjoyed speaking to both  

  • David and Jonathan. They helped simplify what  is a complex topic and put some things into  

  • perspective for me about it. I won't liewhen I was an athlete, there was plenty of  

  • times when I would compare my heart rate to  others and think, "Are they fitter than me?"  

  • Clearly, as we've heard, that isn't the  case, and we shouldn't be doing that.  

  • What about you guys? Please let me know  how you monitor your levels of fitness and  

  • if you do that based on your heart rate. I  hope you've enjoyed this video and you've  

  • learned something from it, so please hit that  thumb-up, like button if that's the case.  

  • To get all the other content on the  channel, don't forget to subscribe  

  • and hit the globe. [00:13:06] [END OF AUDIO]

Fraser Cartmell: Here's a question for you, do  you monitor your resting heart rate or indeed  

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心跳(Does A Lower Heart Rate Mean You're Fitter? | GTN Does Science)

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    joey joey 發佈於 2021 年 08 月 29 日
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