Some experiments “in the field” with HRV.
I’m not going to talk about Heart Rate Variability, there is already plenty of documentation on the web.
Wikipedia is a good start point:
I want to talk about my experiences in the field either while mountain biking and while doing sessions on the gym.
HRV is controversial, at least it should help to determine your recovery status.
With HRV you can plan a training ( or an adventure…) in the very right moment.
With a daily measure of your HRV you can have an idea of the increasing or decreasing of your resilience.
You can evaluate you response to different training loads
Some studies suggest that:
* HRV is age and gender dependent
* HRV has a circadian rhythm
* HRV may change day to day with your biorhythm or due to emotional or physical stress
* Chronic low HRV is an indication of systemic health (psychological or physical) issues
I use a geonaute ant+ chest strap and my phone as a receiver ( samsung S4 ).
I’ve been recording all my activities and every morning I do a couple of tests with two android software:
Pulsometer and Lepo.
Both are free and they are quite different:
Lepo measure the HR ( Heart rate ), HRV and Orthostatic. The measure lasts only one minute.
Lepo link http://lepo-app.net/
Pulsometer is a much more sophisticated and complete software, the HRV beside the HR is recorded and can be exported for a further analysis ( with the free software Kubios, for example ). The measure last for 5 minutes giving a more stable value.
Here the main features, this application is under heavy development and the developer is very keen to feedback and/or user requests:
* Quiet Basic fat burning / aerobic
* Custom zone letting you know how long you’ve been in a range that have marked your HR.
* HR Maximum and average heart rate
* Calories consumed, you can change the type of activity at any time (football, running, etc ..).
* HR zones: Percentage in real time.
* HR Courage absolute and percentage always available, click on the centre marker to change the absolute value of the percentage, however always have the two data visible though a smaller one than the other.
* How To ALWAYS ACTIVE DISPLAY: keeps the screen always on so you can see your pulse at any time. In this way the wallpaper is black and only the pulse is, so you can always see your pulse without searching for the button on your device. When you enter this double tap the screen to activate ON mode so you can see the rest of the plot markers and the last 10 minutes.
* Quick to toggles without entering the configuration menu (sound, screen always on and enable/disable power saving)
* Historical activities with advanced statistics.
* Module HRV: Find your heart rate variability data in 5 minutes and export your data to import into desktop programs as Kubios, ARTiiFACT or HRVAS. Unique ANT + application on Google Play which allows you to export your data RR without integrated application purchases.
* BLUETOOTH and ANT+
You can enter you age, weight, etc. or, much better, your Maximum Heart Rate (HRmax).
Pulsometer gives you the “raw” HRV ( rMSSD ) while Lepo and other software give you the natural logarithms of the RMSSD multiplied by 20. You have a bigger number that can be useful for a fast screen of the results.
I’ve suggested to the Pulsometer developer to provide the same value, anyway the calculator in my telephone has the ln ( natural log ) and it takes few seconds to transform the rMSSD.
The practical stuff.
As you can see on the attached plot (link at the bottom of this page ), the HRV and Rest Heart Beats ( Orthostatic doesn’t seem very consistent ) plots sometime are reversed…well, this happen every single Mountain Bike excursion.
The more was the exertion, the more the two line are reversed!
Just to have an idea: the lines reversed with 6-10 hours of biking with 2500-2800mt of climbing.
In the gym I use to pedal at the maximum of the effort with a slow cadence, it is about an 70-80 minutes with an average of 225W..quite hard for me! After this cardio training I use to do some lighter exercises, at the end of my training I’ve burned 1600 Kcal in about 100 minutes.
As you can see in the plot these “strong” exercises doesn’t inverse the lines. I take this as a solid indicator of how your body react to the prolonged fatigue:
I wouldn’t have said that gym training and the mountain bike session where so different in terms of fatigue but having had a deeper analysis of the instruments here comes the reasons why the lines didn’t reverses as with the bike exercises:
if the burned Kcal can give an idea of the effort that was from 6000 to 10000 for the MTB “tours” and 1500 to 1700 for the gym exercises.
I didn’t see any variation related with the stress, neither biorhythms but I saw a fall in the HRV value during a period where I got the fever .
Some interesting reading:
RMSSD and software