HRV or Heart Rate Variability is a measurement used in the medical field and has been adopted by the fitness field.
But, what is it?
Why is it useful?
Is it useful?
Should I use it?
Why do I recommend it to some clients and not others?
Let's start at the beginning.
What is heart rate variability?
It is quite literally a measure of the variance in the hearts rhythm.
Here's an example, imagine your resting heart rate is 60 Beats per Minute (BPM)
That would be an average of 1 beat every second.
But, we are not clockwork, we do not tick once per second.
The heart beat may fall on 0.9 of a second then 1.3 seconds, then 1.1 second then 1.4 second then 0.8 second and so on.
Yes, over a minute it may beat 60 times, just not on the second, every second.
Sometimes just before, sometimes just after.
The space between beats varies.
That is heart rate variability.
And it is a clear indication of your arousal level, or state of the nervous system.
Most recording tools have some fancy algorithms being used that turn this reading into a score from 1-100.
What does this tell us?
Simply put, the more variance we see, the less aroused we are, and the higher that score is out of 100.
Arousal in this case refers to the sympathetic nervous system ie our stress response, keep your mind out of the gutter!
As your arousal goes up, the variance drops as the heart beats become more regular or rhythmical.
A high HRV suggests good health and all the stuff that goes with it.
Easy recovery, good cardiovascular health, calm mind, good digestion, easy sleep and ready to go at a moments notice.
A lower HRV number may indicate less of these things.
It may also indicate that you're a more explosive type of athlete rather than an aerobic machine.
Power athletes will have a lower HRV score than Endurance athletes, that’s just the nature of the beast, it doesn't mean one is better or more healthy than the other.
Lot's of “may” and “suggests” being used though eh.
Not a lot of definite points you can hang your hat on.
Your actual HRV score out of 100 is not actually that easy to change unless it's low due to health problems.
Sometimes something as simple as a change in diet, a reduction in alcohol or caffeine consumption, a better bedtime routine to transition into sleep better or even a change in your job can reduce the stress load on the nervous system and the number increases a few points.
This would be the primary reason to track HRV, tracking the changes you're making in your lifestyle to ensure they are working for you.
An increase in this number that sticks, probably indicates you're on the right track.
If the HRV lowers, wrong track.
However, most HRV apps are sold as a way to gauge recovery and predict readiness to train.
This is where the fitness world has grabbed it and run.
Yet for most regular gym goers this is nothing but another distraction. As are most of the “fitness industry” marketing recommendations.
For serious and professional athletes, different story.
.
If you train daily, or even multiple times per day, especially across a range of modalities with different coaches, it might be useful to have an objective read on your readiness so training can be adjusted in real time.
It can guide how hard you train on any given day and also indicate if the training is working over the longer timeline.
The readiness is given in a number out of 10. The scale goes 1 - 10 - 1, a bell curve if you like.
On one side it shows you shifting towards sympathetic dominance, or high arousal, the other side, parasympathetic or low arousal.
The closer you are to the middle, to the 10, the more ready you are to kick arse and take names.
The further out, closer to the low numbers, the more likely you need to back off a little, increase calories, maybe even rest.
A number of low scores in a row may predict an illness.
The day after hard training, the day of an event, the morning after a few beers will all push your readiness score down.
Yes, I said the day of an event, when you would want to be a 10.
But pre game nerves will be a factor that shows up on the readiness score. To be honest, you're better not measuring HRV for a couple of days pre event.
Remember, this is a measurement of your heart, which is responding to your central nervous system. It can only show you how far to sympathetic or parasympathetic you are.
So all readings should be taken simply as data and nothing more.
Who do I suggest use this?
Hard working athletes and chronic illness sufferers.
And maybe those trying to make a significant change in their health.
Hard working athletes need to ensure they are working hard enough but not over training. To ensure they are getting adequate recovery. HRV can be a big help here.
Chronic Illness sufferers are actually where I, as a coach, find this most useful.
Many chronic illnesses present in peaks and troughs, and usually as a response to the central nervous system.
When you are under a lump of stress, the illness often shows up worse, and vice versa.
The HRV score then can guide you on training and other lifestyle factors by showing you how the body is responding to the various stressor placed on it. Including exercise.
The readiness score presents with traffic light colours, green for the high numbers, yellow for the middle and red for low.
When green, go wild. It's PR day, Train as if your life depends on it.
Yellow, pull back somewhat, maybe reduce volume or intensity (not necessarily both)
And Red is a signal to back right off. Keep a workout short and sharp, in and out in no time at all, or consider simply going for a walk, or even, putting your feet up for the day.
You make the decision based off matching your subjective experience with the objective HRV reading and looking at the events of the few days prior and what's coming online the next few days.
The HRV reading isn't the answer in itself, it is evidence that helps guide you to finding the best answer.
So long as you use it well.
And that is where a little bit of reading and asking questions of your coach comes in.
Final point.
Many wearable apps simply cannot give you an accurate reading. A good chest strap heart rate monitor that is HRV enabled (most modern ones are) is the most accurate, there are also finger sensors that work well.
Wrist worn devices simply don't have the contact to get a good read. And I can't speak for the ring thing.
Readings are best taken at the same time of each day, ideally on waking. Sitting or lying in the same position so as to ensure consistency. Sitting gives a different read to lying.
And the results only really become useful if you have a bank or readings, taken 3 or more times per week over a number of weeks. This is so the algorithm can do all its mathematical jiggery pokery and be as accurate to you as possible.
A reading takes a couple of minutes. Plus whatever set up time.
The main drawback is that the mobile app puts your phone in your hand first thing in the morning. Which is something I personally would rather avoid.
I guess it's a small price to pay.
Of the Apps, there are a growing number and many are subscription based.
I have used and do recommend EliteHRV as it is free to the user. When I have people on it, I pay a wee subscription that means I can host a group where I can see my clients results.
Clients cannot see each other.
I hope that helps answer the common misunderstandings that surround HRV.
It is one of those tools that can be very useful is used well by those who would benefit.
And one of those tools that can distract those who don't need it.
Which is something the marketing folk tend not to tell you.
Once you learn to actually tune into your own arousal state subjectively, do you need an objective measure?
Does the objective measure help you learn to the skill of Interoception ? Possibly.
As ever, if you have questions on this topic, or a topic you'd like discussed in future newsletters, hit reply and send it in.
I enjoy hearing from you all.
These newsletters are also becoming videos on the YouTube, if you prefer watching/listening, try those.
And for all the online clients, you should have had an email inviting you to the weekly online training meet up call.
If you didn’t, ping me.
Chat soon.
Dave
Regards
Dave Hedges
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