The Time-Crunched Cyclist Podcast by CTS

3 Reasons Your Exercise Heart Rate Is So High (#226)

• CTS • Season 4 • Episode 226

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OVERVIEW
Sometimes your exercise heart rate seems higher than normal for a given power output and perceived exertion. Beyond the standard variables that affect heart rate, like caffeine, dehydration, anxiety, and fatigue, there are other training and nervous system related factors that may elevate exercise heart rates for a few days or up to two weeks. Coach Adam Pulford examines three common scenarios that can temporarily jack up your exercise heart rate.

TOPICS COVERED

  • What influences heart rate
  • Scenario 1 - first indoor trainer session
  • Heat training for indoor cycling
  • Scenario 2 - time away from training
  • How to mitigate elevated HR issues when returning to training
  • Heat exposure to mitigate elevated HR
  • Scenario 3 - long steady rides vs. hilly rides
  • HR response to cold vs. heat
  • MTB Tip - using hrTSS to evaluate technical terrain

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HOST
Adam Pulford has been a CTS Coach for nearly two decades and holds a B.S. in Exercise Physiology. He's participated in and coached hundreds of athletes for endurance events all around the world.

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Speaker 1:

From the team at CTS. This is the Time Crunch Cyclist podcast, our show dedicated to answering your training questions and providing actionable advice to help you improve your performance even if you're strapped for time. I'm your host, coach Adam Pulford, and I'm one of the over 50 professional coaches who make up the team at CTS. In each episode, I draw on our team's collective knowledge, other coaches and experts in the field to provide you with the practical ways to get the most out of your training and ultimately become the best cyclist that you can be. Now on to our show. Now on to our show. Welcome back, time Crunch fans. I'm your host, coach Adam Pulford.

Speaker 1:

The question for today why is my heart rate so high? It's a common question I get from my athletes, people I ride with and some of you, our listeners, who have been writing in lately. Of course, there's always a different context behind each individual question, so what I'm going to do today is share a few scenarios when I've gotten this question and do my best to answer why your heart rate would be higher than normal for a given effort workout, ride or race. Before we get started, I want to remind everyone that heart rate is a wonderful tool in monitoring exercise training and performance, but it has a lot of variability to it. Now, I don't mean heart rate variability either. That's a separate thing. What I mean is that you have many things that can influence your heart rate during a workout or even at rest on any given day. Simple things like how much caffeine you had, or how much caffeine you wish you would have had, how fatigued or fresh you are coming into a workout, the quality of sleep the night before, how motivated or unmotivated you are, and the list goes on. I'm giving you this disclaimer because in every one of the scenarios and reasons that I provide for answers, there's still maybe other aspects that are going on to why the heart rate could be strangely high compared to whatever your normal heart rate is. So let's look at a few examples and hopefully this helps everyone listening, help to diagnose a reason or at least give you more confidence as to the fact that it's not all lost when you see a high heart rate response, or maybe it's slightly elevated.

Speaker 1:

So here we go. First scenario your first hard indoor trainer session. Now, if you're jumping on Zwift and you do a group ride or a race for the first time of the season, let's just say it's a hard effort. Uh, rpe of eight, nine, 10, and you're seeing high heart rates that are higher than normal. So it's maybe like five to seven, maybe even sometimes up to 10 beats per minute higher at threshold or above. Um, that's not uncommon to see and normally when that's happening in my athletes or in some other people's consults or something like that, I'll see the power is within range. But what we're talking about is the heart rate being higher than normal, and so this is simply a cooling issue.

Speaker 1:

Okay, quick advice use a fan to help cool yourself. Check the room temperature. If it's, you know, in the upper seventies or eighties, just bring it down. Whatever kind of like normal room temperature you're living in, I would bring it down, maybe even the sixties. If you can't do that, the fan definitely will help. Okay, and when you do that, you'll see heart rate as well as rate of perceived effort come down.

Speaker 1:

Now keep in mind these heart rates, these high heart rates. They don't indicate high performance. If you're not cooling yourself properly. You're likely doing normal power outputs, but you're more stressed than you need to be because your body is trying to cool itself so much. Always check your power and your heart rate when this is happening and compare past power durations to your own data to see if the heat was the stress or if the power was higher. Sometimes, though, if you jump into that Zwift race and you're super motivated and you're smashing power and going really good, you'll see super high heart rates. Okay, and maybe you're doing peak you know peak powers than you've ever done before. That's a good thing. Recall that when you push on the gas pedal real hard, your heart rate should go up. That's normal and that's healthy. Okay.

Speaker 1:

So let's get back to the scenario where it is your first indoor training session for a while. You're going hard, but you're seeing those high heart rates. It also not shouldn't freak out about it, because it's kind of a new stressor. Okay, especially with the heat. Um, and if you just keep on doing a few more sessions like that one or two times per week, your perceived effort and the heart rate will come down as your body adapts. And so you're saying, okay, adam, it's a cooling thing.

Speaker 1:

What about heat training for indoor cycling? Yep, that's a thing I actually get into how to use a sauna for this. We get into more about the nervous system and things like that, which I'll cover on this podcast. Go ahead and check out my interview with CTS coach Lindsey Golich and it's entitled unlock peak performance heat training strategies and that episode is number two 14. We go deep on how to use heat and I'll leave it there. But to keep it simple, if you're going to do Zwift races and hard training sessions, uh, just put a fan on to cool yourself properly. Do sessions regularly and your body will adapt by increasing plasma volume, which happens from just normal endurance training and hard interval training. Okay, but it's also the end goal of heat training, so you can skip the fan on your zone two rides. If you want a little extra heat stress, just remember to hit the fluids during and after your training sessions to help your body recover and adapt properly to expand that plasma volume.

Speaker 1:

Okay, let's talk about scenario number two, and this is when you've had time away from training. Here's a common question that I got recently. I took two weeks off from training to fully recover. Then started back with endurance riding. My heart rate is higher than normal. Why is that? Did I lose all of my fitness? Okay, and this question came from Gina, a listener on the pod, and it was also a topic of a discussion I had with coach Julie Young from Fast Talk Labs recently. Many athletes experienced this, so let's start to understand why that would occur and know by the way, gina and listeners, you didn't lose all your fitness. Okay.

Speaker 1:

So this happens for many reasons. Some are complicated, some are simple. The primary reason is you decrease blood volume. In particular, you decrease plasma volume when you take a break from endurance training. Plasma is the watery portion of your blood that helps with many things, including cooling yourself through sweat and making your blood more viscous so it can flow through your body more quickly and efficiently. When you take time off from training, your body's quick to respond to a few of these things, including plasma volume. It sees no need to keep that much fluid on board, so it loses some of that plasma, since it doesn't need it. This actually is a good thing, because there's a higher cost to having that adaptation. There's checks and balances within your body to indicate when to take on those high costs and when to get rid of it. It doesn't want to spend any more energy than it has to, so it simply dumps that water. This is if you don't need it, you get rid of it. If you don't use it, you lose it.

Speaker 1:

So, like I said, that's the primary reason that a lot of people who take some time off experience some high heart rates when they come back. But what are some other reasons why your heart rate would be high? Or maybe your rate of perceived effort would be higher during, when you resume training after a detraining phase or a bigger block away. One of these reasons is having an elevated sympathetic nervous system. Okay, now, this can get pretty complicated, but to make it as simple as possible is when, when you exercise regularly, it helps to regulate and balance the autonomic nervous system. So when you train a lot, then stop. The sympathetic nervous system, which is the fight or flight, and the parasympathetic nervous system, which is the rest and digest, can get out of balance and a complicated system like this which governs anything from brain and lungs and heart, everything, the whole body it gets thrown out of whack. I'll include some further reading on this and I'll link it in the show notes. But the sympathetic nervous system can be a little bit more revved up after detraining phase and can lead to some of those higher heart rates too. Okay, I'll talk about this in some and how some heat training can also regulate that. I'll leave it there from now. Let's just keep it simple and say when you do 50 weeks of training per year, that nervous system gets used to something. When you stop doing it, it gets a little out of whack and it's completely fine for reasons I'll go over here in just a second.

Speaker 1:

Another reason could be some glycogen depletion. Now you might think, well, I just took a big break, why wouldn't my body be fully replenished on glycogen? Well, this gets back to the acute responses to endurance training. If your body recognizes that you're not training as much, it's going to deplete or not uptake as much glycogen as it would be while you're training. When you go out and you do long rides or hard sessions, you deplete muscle glycogen. Your body's response to that is load back up and maybe carry a little bit more. So this isn't like super low or low, low or even a primary reason, but it could be one of the reasons Cause you come back and do a three hour ride. You don't have as much muscle fuel on board. Body gets more stressed, a little bit higher heart rates One of the reasons.

Speaker 1:

Another one is muscle deconditioning. To make this one simple, this goes back to if you don't use it, you lose it. That's the concept. When you work and you train muscles there's cellular efficiencies that go on. When you take a big break you can diminish that. That's part of the detraining process. But don't worry, they'll come back really quickly.

Speaker 1:

I like to say easy come, easy go. But it's also easy go, easy come, okay. So think about that and just know that there's some cellular efficiencies going on that quickly turn on and off. Lastly, we have reduced cardiovascular efficiency. Now your heart is a muscle, so, just like in the muscle deconditioning aspect, that muscle detrains a bit. Additionally, remember the decreased blood volume aspect.

Speaker 1:

That's another big one. So if you smash back into heart training after two weeks off, your heart rate could just be. You know working in overtime because it is super stressed If you go come back too hard, too quickly. But if you ease back into training, okay, with some aerobic zone, two rides before you progress up into intensity, things will go a lot better. So more on that in like 30 seconds, because it starts to answer the question of how do we mitigate these issues. To answer the question of how do we mitigate these issues, well, when you take a break and you fully restore the body.

Speaker 1:

Some of the cons come with these pros. The pros, or the benefit, is full restoration, and that's part of being healthy. In the big picture, the pros of recovery and restoration outweigh these little cons, which are short-lived, and that good news is that much of these issues that we're talking about are, like I said, acute changes to endurance training. That means they go away quick, but you can get them back relatively quick and you'll be stronger and better off for it, especially the plasma volume. So, just like when I was talking about easing back into training after you take a big break away, I recommend taking five to six days of regular riding and training and the heart rate response should start to regulate as plasma volume starts to increase. So what does that look like? Two to three days of endurance, okay.

Speaker 1:

So if if normal training, you know you were doing that uh, anywhere between four and eight hours of training per week in regular rides were, you know, around an hour 90 minutes of training, I would come back and just start back in with an hour 90 minutes of aerobic riding. Do that two or three days in a row and on the fourth day you can hit a threshold session like three by eight or three, by 10 at threshold, or you can hit a group ride and that first ride you probably see that heart, that high heart rate response, and in RPE go up a little bit. And then you do some easy rides. After that take a rest day and that second week then Okay, so that's like the first week that you come back into it. The second week you'll you'll start to regulate. Okay, everyone is a little different but I find, um, that works. That routine can help work pretty good for most people. I'll encourage everybody to find a routine that works for them, but the takeaway is, uh, for most everybody. I would start back with simple zone, two rides.

Speaker 1:

So what are some other hacks? Use heat, okay, coming back to heat training, for this in particular, we're using a sauna and we're going to use a sauna to help regulate that sympathetic and parasympathetic nervous system. Remember that when we train properly, with adequate recovery, our autonomic nervous system, which covers both of the ones I just described, it balances itself out nicely. Okay, one, one quick side note here I'm not a hormone expert, okay. In fact I've told my athletes that I'm pretty good at figuring most things out, except when something goes haywire or you have an injury, a head injury, for example. So head injuries and hormonal imbalances, that's when we get experts. Okay. So I'm just talking like high level stuff. That's in the research stuff that I'm using, um, uh, experientially in my training. Okay. So if it gets more complicated than that, I'm not the expert here. However, this is all uh, well proven and documented and, um, if you want to read more about it again, go into the sites that I'll post on the show notes.

Speaker 1:

Okay, so regular training balances the autonomic nervous system. There's good research to show that regular hot or steam room temperature can stimulate the sympathetic nervous system. So elevating that heart rate up a little bit with heat, which then gets balanced out by the parasympathetic system when you come away from the heat so artificially warming up the body and then coming out and cooling the body Effectively you can use this heat during your detraining phase to mitigate some of these higher heart rate responses when you resume training. Now, if you do it right, like Lindsay and I talk about in our episode, you probably also maintain some blood volume as well and retain that plasma, so you won't get diminished there too. But please hear me on this If the intention is to detrain, or if you take a vacation for a couple of weeks, I want you to enjoy it.

Speaker 1:

Spend your time doing fun things other than endurance-y things. Okay, that will help your brain reset too, which is all part of it. I don't want you hanging out in a sauna and getting trained up in heat during your detraining phase. Okay. Now, if it naturally occurs and you go to a place that has a sauna or something like that, sure do it. It's very relaxing, it's very healthy and it can maybe help mitigate some of this stuff. But do it all in balance.

Speaker 1:

So here's a third scenario long, steady rides versus hilly rides. This might be counterintuitive to some, but you might have higher average heart rate on long, steady, flat rides versus hilly or punchy rides. One common thing I see in many athletes this time of year is when they've been training outside during a nice weather so summer and then it turns fall and winter, cold, they started doing indoor rides of similar duration. So that's 60 to 90 minutes, maybe two hours, and they've ride. You know, could be even zone two, maybe they stick to zone two or they get sucked into the you know, the hard group ride or something like that, and they just pedal, pedal, pedal and they see that heart rate go up and all of a sudden, training peaks or whatever you use to manage your data, it's. It's sending you those push notifications of peak 90 minute heart rates of the year. Peak two hour heart rates of the year. Peak two hour heart rates of the year.

Speaker 1:

But maybe the power is the same. What's going on there? Well, cooling, just like I said before, use a fan and mitigate that high heart rate. But you're also just pedaling a heck of a lot more. There's less descending on Zofia so you can pedal more. There's no stop lights and stop signs and really, if you look at the power distribution and pedaling distribution on a file inside versus out, you'll have maybe 1% of the time spent in uh, you know power zero to 10 versus on an outdoor ride where, if you're drafting or descending, it can be, you know, on a hilly ride up to 30% of your time spent in zero to 10 watts or recovery miles at zone one, okay.

Speaker 1:

So, very simply put, if you're doing long, steady rides on Zwift or maybe it's a super long gravel ride with nothing else going on and you do that for the first time, you'll average that higher heart rate simply because there's more time in zone. So I think when you're riding inside in a virtual environment like Zwift or TP Virtual, I think that should make a lot of good common sense. But when you're outside, is there anything different going on? This came up recently when I was working with one of my athletes and he asked me why is my HR TSS greater than my TSS from power on these three rides? So before we get there, quick side note, recall that TSS is a training.

Speaker 1:

Stress score is generated from normalized power relative to your functional threshold power. You get a stress score based on how much time you're riding and how much time you spend in and around your FTP. Ride longer and easier, rack up the points, ride harder and shorter. You can rack up the points and if you don't have a power meter, you can use heart rate monitor to generate a TSS score. This is based on your average power relative to threshold heart rate. If you use both heart rate and power during training, the TSSs should be roughly similar, but there are times when they are different, especially if your ride has an abnormal amount of pedaling, like the flat rides that we were just talking about, or has really hard efforts where there's not a lot of pedaling like in crits, okay, where you're on the pedals and off the pedals. You're steering, you're driving the bike, it's high stress and so the heart rate is just pegged and you could just be sitting on someone's wheel. Okay. So big short burst of high power effort combined with just being either super stoked or super stressed, that's going to drive the heart rate up on things like that. So anyone can toggle between their HR TSS and their TSS for any ride if they wish, and in general I would go with the higher of the two, especially if the effort felt harder than the reported TSS on one or the other.

Speaker 1:

So my athlete and I spent time looking at these three rides two flat, steady rides that he normally doesn't do and one hilly ride for him, which he normally does. Each ride was zoned to intensity and intensity factor with a few splashes of tempo zone three, but nothing super duper hard. The normalized power for the hilly ride was higher than the flatter rides, but the time he spent coasting was higher on that ride, so heart rate could recover and thus driving the average heart rate lower on the hills ride. On the flat, steady rides there was more pedaling and therefore more time in zone at zone two, racked up, and the average heart rate was higher, with no breaks. Each of these rides were right around three hours up and the average heart rate was higher, with no breaks. Each of these rides were right around three hours. So combine that with the fact that my athlete was rolling off from a little bit of an injury and some work travel where he wasn't riding as regularly for a couple of weeks, he had higher average heart rates than normal, given the power, and we were seeing some of those peak 1.5 to three hour heart rates of the year. Nothing to be concerned about here, because a week later we're now back into the normal heart rate training ranges.

Speaker 1:

Rpe came down and everything's good. The Hills Ride had a higher TSS from the power standpoint as the descents allowed the heart rate to come down a little bit more, but again the normalized power was higher, even though the normalized power for the day was still zone two, because we're just climbing a little bit harder. It was really cold that day too. So he asked if a heart rate goes up in the cold, such as the heat, just from a stress response, and I told him it's a good question but no, it doesn't work like that, but I do find that athletes, including myself, do tend to ride on the higher side of things, especially like high zone two or low zone three, just simply to stay warm. So you combine a cold, flat, steady ride where you're just trying to stay warm and you're pedaling a heck of a lot more and you're outside. We'll see those higher heart rates.

Speaker 1:

Now, if you haven't done a longer steady flat pedal in a while, either inside or out, go try it and see. Start to compare that with your, like your hilly ride. Or if you haven't done hilly ride in a while, do that and start playing around with the HR TSS and the TSS. Now, when you do these rides, still try to match up the RPE on both of them. So if it's an endurance ride, rate of perceived effort should be four or five out of 10. Okay, so do those rides, gather some data, play around with the TSS and see if they're similar or if there's discrepancies.

Speaker 1:

And one quick tip for my mountain bikers out there this is something that I do on a regular basis is if you ride somewhere abnormal for yourself, that's like overly super techie and you come out of it and you're like man, my whole body's tired. Try using the HR TSS If you were a heart rate strap and see if it's. If it's higher, normally it is, and then I would use the higher TSS score to manage yourself and with the performance management chart, and manage your CTL, atl and TSB. If it is higher, you want to know that the stress was higher. That's the main point. You would rather undertrain yourself by 10% rather than overtrain yourself by 1%. Train yourself by 1%. Okay. So using the higher stress score, in my opinion, is a better thing when you're looking at how best to manage and determine what's next in training or how much recovery that you should have after a training session.

Speaker 1:

Okay, so to wrap this thing up, hopefully you've learned that a high heart rate response can be a normal thing when you start riding indoors again for the season, or after you take a long break and you resume training, or on days where you're just on the pedals more than usual. Some of this is easily correctable and some of it you just have to be patient, stay the course and let the body adapt. Heat training, like using a sauna, can help to regulate the body during periods of low training and help to mitigate high heart rate responses when you come back to training. Additionally, that high heart rate response itself is not performance. It's a response to the effort that helps bring more information, more quality, about the performance or the training session session. So the main thing I hope that you all can take away from this is how to diagnose when the response could be different, using other things like power, speed, rate of perceived effort and historical routes or training data to compare apples to apples before having any emotional reaction to the heart rate itself. And finally, sometimes, when you're just redlining and you're going really good with some of the best effort and best power of the year, you should see a high heart rate response, and that is awesome and that is healthy. So don't overthink it, but be equipped to be educated about why you're seeing these high heart rate responses. So that's it. That's all for today.

Speaker 1:

Thank you again for listening to the show. If you enjoyed this podcast, please share it with a friend. It's the best way to grow the show and ensure that we're pumping out great content for you, our listeners, so that you can keep on coming back and hearing more good tips. Now, if you have a question that you can't figure out, head over to trainrightcom backslash podcast. Click on, ask a training question and those get sent directly to me and the podcast team and we'll do our best to answer it on a future episode. Be sure to come back next week for more training tips and subscribe to the show so you don't miss an episode.

Speaker 1:

Thanks, folks. Thanks for joining us on the time crunch cyclist podcast. We hope you enjoyed the show. If you want even more actionable training advice, head over to train rightcom backslash newsletter and subscribe to our free weekly publication. Each week you'll get in-depth training content that goes beyond what we cover here on the podcast. That'll help you take your training to the next level. That's all for now. Until next time, train hard, train smart, train right.

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