Heart Rate Variability (HRV) for triathletes with Dan Plews | EP#42
Dan Plews (The Plews), PhD, is a world-leading researcher in the field of Heart Rate Variability (HRV), and an elite-level coach.
Today, we discuss how you can use HRV as a tool in your triathlon training to find the right balance between rest and stress, to help push your rate of improvement in the sport and give you an extra edge.
In this Episode you'll learn about:
- How HRV can help you decide when to do high-intensity workouts and when to hold back, and why that may be better than sticking to a rigid program
- How to use your HRV baseline as a tool to help determine if your training load in a block of training is appropriate, too large, or too small
- The tools, apps, and resources that the Plews recommends using to get going with HRV
About Dan Plews
- Did his Ph.D. in heart rate variability (HRV) which he finished four years ago.
- He got into this field research because of Professor Paul Laursen, “The Prof”.
- Together, they now coach and consult at Plews and Prof.
- He is a research fellow at Auckland University of Technology in which he supervises several master students and a few Ph.D. students, looking at various aspects of sports performance.
What is HRV?
- HRV means Heart Rate Variability. What we are actually looking at in HRV is the gap between each heartbeat. The gap with each heartbeat is not the same, it varies all the time.
- We measure HRV in milliseconds (ms). Some heart beat intervals may be 800 ms, some 1000 ms, and some 1100 ms, for example.
- There’s a larger variation between beats when we are in a rested state.
- The reason we’re interested in this is because it’s actually linked to your autonomic nervous system.
- The autonomic nervous system has two branches: the parasympathetic and sympathetic branches. The sympathetic branch is your fight-or-flight side, which dominates when you’re most stressed, particularly during exercise. The parasympathetic side is often called rest-and digest which is the side that dominates during relaxation and generally when you’re in recovery state.
- They key is that HRV can actually measure this. When there’s more variation between beats, it means that we’re more in a parasympathetic or relaxed state. If there’s less variation between beats, it means that we’re in a more sympathetic or stressed state.
- When you’re exercising, your heart rate is up to 150-160 and very steady, meaning there’s not really much of a variability in the gaps between each heartbeat.
What are the implications of HRV?
- Research suggests that when you wake up in the morning, you take your resting HRV and when variation between the beats is low, you’re in a more stressed sympathetic state. Maybe you’re not as recovered as desired from your training. As a result, you would actually decide to do more of a low intensity session on that day.
- Conversely, if you wake up in the morning and your HRV is normal or high, you would actually decide to do high-intensity training on that day.
- In a lot of our research, we found that the real practical application of HRV within an elite group is harder than it seems. The general day to day variation of HRV is very varied anyways so we moved away from looking at HRV in an acute response to more of a chronic standpoint alongside subjective metrics.
What are the differences of the acute and chronic views of HRV?
- When we say acute it is making a judgment call of what to do in your training based on that acute response of what your HRV is on that day, that very split second in the morning.
- What we did was that we showed those acute values can be just too varied and cannot really mean much.
- But when we showed them in a rolling average, whether that might be a 7-day or 10-day period, it tends to be more stable and we can get more certainty in the decisions that we’re making based off that.
- So we devised ways where we would look at baseline measures for an individual and establish ways to measure that baseline. And then we would look at how those rolling averages would respond over a training block.
- What is being shown time and time again when you’re doing endurance polarized training is the natural response that you’re going to see when you’re adapting/coping with the training.
- The response is that you would see an increasing trend in the baseline. If you look at the rolling average of a 7-day period when you’re doing a good block of training and you’re making some good adaptations to that training, you would really see an increase in that HRV rolling average.
- But that doesn’t necessarily mean that you’re going to perform well at that time. It just means that you’re coping and adapting well to your training. But if you’re actually to compete at that time, you’ll probably be a little bit tired and wouldn’t go that well because in performance, freshness comes before fitness. You might be quite fit but you also have to be fresh.
- So what we found is that when you’re actually tapered, the HRV would then come back down to baseline. But what you want to see is that it comes up and back down for the optimal time before competition.
How do you measure HRV?
- We’ve made really good expansions in the way that we can measure HRV now.
- There’s a lot of iPhone and Android applications that measure HRV, and you don’t even need a heart rate monitor and a chest strap.
- We can now measure HRV using PPG technology using the camera at the back of the phone.
- We published a paper about 3 months ago that validated an app called HRV4Training that uses that PPG technology. And we validated it against ECG and they’re very close and reasonable in terms of the measurement of measuring HRV. There’s also the Elite HRV app that you can download. So you can download these and use them on a daily basis.
How to set your HRV baseline
- With the HRV4Training app, I’ve had a lot of involvement with the coaching app where we established an advanced setting that sets your baseline for a period of time that you want it to be at.
- For example, I would establish a two-week period for my athletes where they are training well - at 100% of their training load. Then I will establish the baseline from that period.
- What’s really important is that you establish the baseline in a period of time when you’re not stressed, when you’re not having a high training load.
- Then after a year’s time you might do another two week period where you establish again. And this is one of the benefits of the HRV4Training Coach app.
What are some practical tips than you can give if people want to start using HRV?
- HRV is very content specific. So, you have to really understand the response and type of training you’re doing, as decreases are bad but increases can be bad as well.
- These apps try to make a decision or suggestion to your training based on one number on that day. And the good thing with the HRV4Training app is you get that daily score that encompasses your HRV and your subjective data.
- If you’re an endurance athlete doing a heavy training block, if you’ve got your training distribution right, you should expect to see increases in HRV.
- But if you’ve got that wrong, where you are doing too much high-intensity training, you don’t have that balance of low-intensity versus that high-intensity, you’re probably just creating too much stress for yourself and you will gradually see HRV go down.
- And also, the really good thing about HRV is that it's not just about training. It can be diet that can show on it, and also work and life stress. All these can have a response on your HRV. These are things that you have to be aware of.
How much general increase in HRV can we see over time?
- It’s completely individual. For example, my baseline HRV is around 10 but for some people this is very high.
- What’s important is how much it changes compared to your normal values. You can’t really put a number on it.
- Usually the HRV4Training app a substantial change is still set on one standard deviation. The HRV4Coach app is still on half a standard deviation.
- I typically use 0.5 of a coefficient variation over a two week period. And that’s what’s important: establishing your own baseline and knowing what a substantial change for you is.
What are the actual benefits of adapting your training with HRV and how big are they?
- HRV is not the silver bullet but it’s another tool in the toolbox that you can use to monitor how your training is going. And it can really help with the consistency side by making sure that when you go out you’re hitting the targets in training and you’re not going to be over fatigued and need to take a step back from your training.
- With one of my athletes who was really in a good training block in the build up to the race, the HRV had the desired response. During this block, it really increased and he went above his own threshold. So I knew that he was getting a good adaptive response.
- Conversely, it was the opposite when we started this block and it just started plummeting and going down. Then I have to ask myself better questions, “Why is that going down? Have we got the balance of the intensity wrong? Is the recovery not right?” And I’ll make a change in the program to get the response that I’m looking for.
How much information do you have on your website about HRV? Are there any other resources?
- If you go to our website there’s an HRV tab where you can find all of our publications about heart rate variability. There’s more than 30 publications there.
- A really great resource is provided by Elite HRV who is owned by a great guy named Jason Moore. He actually runs a foundation in HRV Course which is an educational forum and course that you can apply and do.
Note: Part of Dan's answer was cutout due to a bump in the airwaves. He mentioned EliteHRV's and Jason Moore's podcast, but this part was cut out by our recording software. If it sounds like I'm responding to a different answer than the one the Plews gave me, that's why 🙂
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Is there anything else in exercise science that you’re greatly interested in?
- At AUT University, I was looking at something called functional resistance training which is using these weighted garments for Ironman training which has proven to be quite interesting.
- If we only have a certain period of time in the week to do our training when we’re trying to work, this is just one way that you can potentially maximize your time when training by adding minimal weights like 100 grams on the calf or on the thigh while you’re doing your running. We're even trying to use it in swimming.
- Low carbohydrate diets for Ironman triathlon is something that I’m really interested in as well.
Rapid fire questions
Favorite book, blog or resource related to triathlon or endurance sports:
Favorite piece of gear or equipment:
Personal habit that helped you achieve success:
Connect with Dan
Twitter: @theplews1, @PaulBLaursen and @PlewsandProf
Links and resources
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