The Knowledge is a new podcast from Wahoo. It provides straightforward, science-based, useful information from world-class experts to help endurance athletes maximize their performance. Sports scientists Neal Henderson and Mac Cassin discuss a single training topic in each episode and provide key takeaways to apply to your training.
Glad to see you made it back! In this episode, Neal and Mac are back again to break down how you can train with purpose and what you will need to succeed. Speed vs Power Output, Heart Rate, and Perceived Exertion? What does it all mean and how do we use these specific metrics to our advantage. Find out now on The Knowledge Podcast brought to you by Wahoo.
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Neal 0:00
Hello, and welcome to another episode of the knowledge podcast brought to you by the wahoo sports science team in Boulder, Colorado on Neil Henderson Head of Wahoo Sports Science.
Mac 0:09
And I'm Matt Cassin Senior Physiologist with Wahoo. Today we're discussing why you should use three specific metrics when training.
Neal 0:16
Geez, Mack, that's a lot of things to think about, do I really need three things to think about? While I'm training? Can I just like, go do what I'm gonna do?
Mac 0:24
You can, and that's called training without purpose.
Neal 0:28
Alright, I guess, purpose, you know, the purpose has its place, right? So in this regard, what are these three things you're thinking about? I should be thinking about how I'll do it. If you make me,
Mac 0:39
These three things are going to be output. So it with cycling, we're talking about power? for running, we're talking about your pace or your speed. The next one's gonna be your heart rate, you know, how fast is your heart beating? And the last one is RP or your rate of perceived exertion? How hard does it feel like I'm going?
Neal 0:57
Okay, well, on that first one, so like your output, so you said specifically in cycling, you want to look at power-up, why not speed?
Mac 1:06
For cycling speed is in power are not very dependent on one another, if you're going uphill, you're going to be going slow, you're going downhill, you're going to be going fast power is really effective for recycling and useful, because it's a direct measure of your output. It's taken, how hard you're pushing down, how fast you're pushing down and turns it into a nice simple number in terms of watts,
Neal 1:26
So, Okay, that makes sense. To me, speed is definitely relative on a bike, looking at power output definitely kind of gives us a better, better picture. Are there any other factors that would affect my power output? when I'm writing that I should think about in some cases, or is it just a lot? A lot?
Mac 1:42
A lot is absolutely not a lot. There's a lot of factors going on there more significantly, it's really what is that relative what to you. And so that's where we, you know, we have our four different essentially, power metrics that we use to sort of base your training off of so we know what wattage you know, your threshold power is, what your maximum aerobic power is, what your sprint power is. And so really, it's that power is going to mean something different to two people, if one person special 200 watts, and other persons special 300 watts, or riding at 200 watts is going to be pretty hard for one of them, and it's not going to be too bad for the other one.
Neal 5:09
Exactly. So relative to your ability is what's super important here. Yes, you can compare yourself to someone else. But if I want to look at my power output, or my pace or my speed, I want to think about relative to what my ability is what's sustainable.
Mac 5:30
Gotcha. And so the next one comes out, which is also an individual one is going to be your heart rate, right? So number of beats per minute. If I'm chilling, riding my bike at 160 beats per minute, you know, what is that relative to you? Well, geez,
Neal 5:44
I mean, that's like up over my threshold. Mac, you and I have some some pretty different hemodynamic responses here, our heart rate for a similar relative effort. If we think of like a perceived effort, if we both cruise along it, say a three out of 10 effort, my heart rates, probably about 110 120 beats per minute, and Mac
Mac 6:06
three out of 10, for you
probably about 155.
Neal 6:09
What that's just crazy.
Mac 6:11
I don't think I can get on a bike without my heart rate being about 115. So,
Neal 6:15
Man, I can average under 100 and still be rolling along and enjoying life.
Mac 6:19
I do have what I've referred to as a hummingbird heart.
Neal 6:22
Yep. That's one of the one of the aspects here is just the physical heart size, not your metaphysical metaphor, you know, heart size, you know, not how much you compassion you have and how much you care. But really, just structurally, how big is that heart muscle, the heart is a muscle. And every time it beats, it's pushing out that blood. And so a bigger size, physically, heart will push out more blood, every time it beats a smaller heart comparatively, just doesn't push out as much blood with every beat. And so if a body's demand is kind of a similar, which McIntyre kind of similar size, not exactly the same size, but you know, we're more similar than dissimilar, I'll say, but structurally, my heart is probably just a little bit bigger, and it pushes just a little more blood every beat. And so if we need the same amount of blood being presented to our muscles to do work with a smaller heart, Max is going to go a little faster, mine's going to go a little slower.
Everyone has a resting heart rate when you're just relaxed and sitting down, you know, a normal, the medical stuff we'll say is, you know, normal heart rates between 60 and 100 beats per minute at rest, very common for endurance athletes to have a lower than that, which is actually called bradycardia. In the 40s 50s, even into the 30s. I know some athletes that have had resting heart rates, 2628 beats per minute, which is just crazy,
Mac 8:48
Just as an anecdotal one there, I learned that the heart rate monitors in a hospital room, they will beat if your heart rate drops below 60. And they can manually turn that off. But it will not allow you to go below 40. And so at one point when I had an injury when I was quite fit, and I was a bit sedated at the time, I kept getting yelled at to be awake and do something because my heart would be around 32. And it just really annoyed all the nurses
It'd be higher for if you're doing a similar relative output. Okay? It would be higher, you're using a bit more musculature. There's just more going on. So to make you go forward, you're using more muscles. those muscles need oxygen, each heart needs to pump faster to supply all that oxygen to all those working muscles.
Neal 9:52
Yep. And since you don't know anything about swimming, I'll talk about that. If I jumped in the pool and I'm horizontal and I start swimming at a similar effort as I was on the bike, my heart rates gonna be definitely
Mac 11:01
So when you're talking about given effort here, and you've given the example of going from biking to running to swimming on doing the same effort, what we're talking about there, right is rate of perceived exertion, how hard does it feel like you're going that's really the only way you can directly say that I'm going as hard running as I was cycling. And that's really, as it turns out, in our opinion, that's probably the most important metric of these that you want to be continuously monitoring and checking as you go through a single workout.
Neal 11:29
Definitely an RP, there are different scales out there when when the original scales was actually from six to 20, which was was used and validated in a lot of kind of college age students subjects studies. And actually, if you add a zero to those values, 60 to 200, was kind of going from the average resting heart rate to the average maximum heart rate. And that's what that you know, kind of correlation on the old six to 20 scale is we've we've used a bit more of the categoric scale of one to 10, with 10. Being that all out effort, and one just being kind of doing nothing zero, truly at rest, we typically think of like that break point or threshold FTP type of level being somewhere around a seven, though, again, some people think it's a six or seven or eight. And interestingly, Mac, we have some folks out there that are not very good at using RP are they not terribly reliable,
Mac 12:17
That is correct, they have a sometimes it's a false sense of belief in how hard they're going, they might lie to themselves and say this is totally manageable effort, when in fact, it's probably not going to end too well for them. It is something that as you go through a warm up just any time it's again, if you just keep checking back in with yourself, it's something that you can actually develop as a skill pretty quickly. It's always funny, I think about nine out of every 10 tests we've done here in the labs measuring stuff, we take lactate, we're looking at power, heart rate, and every stage we have to ask the person, you know, what's your rp? and nine times out of 10? They'll get an answer like a two or three, and then I'll be asked if that's correct.
Neal 12:54
Yeah, the answer is what it is, it is your judgment of your effort and how you feel. So we do sometimes have to give a little bit of extra descriptors to help people understand that this is like a global overall sensation and feeling not just like in the one thing, so especially if we're doing lactates sometimes we you know, we're poking their finger, their ear, and you know, You have some nerve endings there. And if you know I keep poking you in the finger with a sharp thing, you might think, Oh, my fingers out a 10 out of 10, that really hurts. But you're jogging along at an easy pace. So it's not like what is your finger feel like? It's like, what do you feel like in total, is that what we're talking about back then Is this what we're what we're looking for.
Mac 13:31
That's exactly
what we're looking for that triangulation of using these three different points to zoom in, make sure that the effort you're doing and training is lining up with what it should be. And that's something that is a again, it's a skill, it's one thing to just sit there and have power targets that you're going to hit and hitting them. And just ignoring your heart rate and RP, that's one thing, it's one thing to just look at your heart rate, which is impacted by a lot of things like stress, hydration status, if you had a bunch of coffee beforehand, or if you're just doing RP, if you're not quite skilled enough at it yet, he's potentially not going to be great either. So again, it's using all three of those in every effort of a ride to make sure that the rides going as planned, maybe you're having a bad day, maybe you're having a good day, you're not really going to know that unless you are checking these three things.
Neal 14:16
So when things are in sync, generally if I'm going out and doing a training session, I have a target pace that I'm trying to hit or output power, I also would have an associated heart rate that would be kind of normal for that effort level based on my current fitness, as well as then a perceived effort that it should feel like that's kind of the idea that you have these really three different ways of assessing then what's going on an actual output power speed pace, then a response like heart rate is actually a physiologic response. In some cases in the lab, we might go into more depth we may look at oxygen consumption, we may look at blood lactate, we may look at muscle oxygen level, we may go in into a greater depth of that physiology. To see what's going on, but when we're outside simplest, easiest to use heart rate is great in that context, and then we have that perceived effort. And so what does it feel like? How long could you sustain that kind of effort, given the kind of fuel that you either have on board already, or that you have with you, if you're on a long ride, these are skills that can be developed. And I would say the best athletes that I've worked with over time and endurance sports, have what I would call almost like a Zen level of knowing these different things. So I could take off their computer and take off the information that shows say, their power, their pace and their heart rate. And I could ask them what kind of power you push him right now. And they know based on the field, that force into the into the pedals, what that power is probably within 10, or 15 watts, they know what their heart rate is within two or three beats per minute. And again, they have that perceived effort, well, it feels like to them, but they could also tell you how long they could go with that effort with with the amount of you know, hydration and fuel they've got on board. Or if they went a little bit harder, how long they could hold and sustain a given effort level. And again, tell you what that heart rate would be and what that power pace speed would be. And that is kind of the ideal that you may have the reference device that you look at and measure it and can quantify it and analyze it after. But you also have your internal computer going on and being able to pull all those things together and be able to make those judgments on your own.
Mac 16:31
Definitely, that's how you're going to get the most out of any training session is, you know, making sure everything's going as planned as expected. And understanding how you individually respond. I think a great example for showing that shift in heart rate and RP compared to power is during just like a pretty standard one minute on one minute off, sort of map vo to type type of work, your first minute effort should be a pretty low RP by the end of it, because it's not long, and you should be pacing it. So you can get through all of them just barely. So you can have an exact pace you hit for all, say 15 of those efforts. And so you have that specific power and or pace and you can nail it every single time. And what's going to happen is your heart rate during each interval is going to be a bit higher, each one successively how much your heart rate drops, after each one is potentially not going to drop as much. And the minimum heart rate will certainly be higher. And your RP is going to go from you know, a five for the first 167 all the way up to 10. And so the output, if you just looked at that power, you'd say nothing changed during that session. But looking at your heart rate. And referencing that RP you can see that yes, this was a progressive workout essentially to max. You know, that's what you want out of sessions like those, you want to make sure you can get through them, but make sure you're just
getting through them.
Unknown Speaker 17:45
One thing to keep in mind is you can use these normal relationships of your pace, power, heart rate and perceived effort to find out when maybe things aren't in a good place for you whether maybe you're coming down with something getting sick, or when you're dehydrated, or when you need a little more rest, there's a lot of different things that can happen. But a couple things to think about. If I if you go out for a ride, and you're going along at a low effort, perceived effort, and your power is kind of low, but your heart rates really high compared to normal 10 or 15, or 20 beats higher than normal, there's a few things to think about a just super stressed out lot going on life work that are just truly resulted in this stress response, that'll increase your heart rate. Well, if so, you might want to think about kind of just easing into things that day, or maybe pulling back on some of the higher intensity because your body's already ramped up a little bit. Other thing is are you hydrated, you know, if you didn't drink any water, and it's hot outside, and you've been just kind of running low on fluid, that's going to increase that viscosity of your blood, low blood volume. And it's going to be more strain on the body from that physiologic perspective and drink a big bottle of water and see heart rate dropped down for that same effort. You know, sometimes that'll happen and just like 10 or 15 minutes and do it. And then another thing that could be happening is if you have a little virus in your system, it's up regulating everything, your temperatures up a little bit higher, your heart rates higher, and you might be able to get through that workout. But if you really say push a high intensity workout that day, you may really find yourself in a big hole and really knock yourself out for the days after. So kind of use with caution when you see that really high elevated heart rate for a normal given effort. What are some of the things that you sometimes see back,
Mac 19:31
You know, a big one can just be if your power is where it's supposed to be. And even if your heart rates generally where it's supposed to be if your RP is just off the charts and super high, you know even even though those two at that output and you know that physiological measurement are in normal ranges, that RP is still really important to listen to because there's a whole host of things that could be be going on there. But generally, our rule of thumb is if you genuinely feel bad even if the numbers Okay, then it's probably in your best interest to just dial things back and not really Push through it. Because if if you're have that sort of lack of matching up something somewhere is off. Another big one is, you know, if you're riding at a moderate power, like endurance and your heart rates really low, and your RPM is about where you'd expect, you might initially say, Oh, great, I'm super aerobically fit. But it's also quite possible that you're just super fatigued.
Neal 20:22
Yeah, sometimes people think about these differences in heart rate like that as a sympathetic response, where you have this upregulation and an increased heart rate as you're going along, because your body's just kind of ramped up. If you keep that up for too long, then you get into this next phase, which is like a parasympathetic, which is basically that sympathetic system is kind of an exhaustion and now everything is slowing down and your heart rate is lower, you can't achieve the same peak heart rate, often you'll see sleep disturbances and motivation changes and all those kinds of things. And in both cases, either in that sympathetic upregulation, you're running it, you know, risky at that point. And if you keep doing it, you get into that parasympathetic aspect where you're really overdone. And I always noticed myself with actually resting heart rate, if I saw really rapid drop in my resting heart rate by four or five, six beats per minute compared to normal that that meant that I was really in that kind of like, I've gone overboard on the sympathetic, and I'm now getting a parasympathetic response. And typically 234 days easier training, just rest, you know, maybe not completely days off, but lower intensity and shorter sessions, bounce back, and I'm ready to go.
Mac 21:34
Like all this stuff, there's always going to be individual variation and how you respond and what you're going to see your body and you uniquely have these different variations that you're going to see that are going to indicate what's going on with your body. And the only way you're going to learn what those mean, and how to act on them is to pay attention to these things in as many training sessions as you can. And once you have more experience and you see trends over time of what's going on, you can learn these individual cues that you have, and that is probably one of the greatest training assets you can have is knowing in a session before you've gone overboard, or before you've undercooked things, if you know that going into it because you're seeing these associations that you know, have a direct outcome for you 2.3.4.5 days later.
Neal 22:18
Yep, definitely. It helps you have that purpose and assess where you're at, track where you're at. And that's often what's helpful in defining and guiding you towards where you want to get. So that's a bit about you know, looking at these three different things. We are definitely going to be discussing these topics in greater detail in coming episodes for sure. So make sure you send your questions our way. Thanks for joining us. Catch you next time.
Transcribed by https://otter.ai