When I first started recording HRV measurements in August of 2011 I didn’t really know what to expect. I had no strategy for how I was going to interpret the data or put it to use practically. Other than reading Q&A posts from Landon Evans on elitefts, I didn’t know too much about HRV. All I knew was that it sounded interesting, logical and it was something cool to buy. I didn’t even own a compatible device to operate the app on so I bought an iPod touch.
Up until that point I was training religiously. Three weeks on followed by a one week deload. I didn’t miss workouts. I would try to hit my planned numbers at all costs. This method of training worked very well. I got big and strong training like this. Upon purchasing my ithlete device I kept my training structure the same and simply recorded HRV every morning. I decided to analyze the data later and see what I learned. Was I stronger when HRV was high? Was I weaker when HRV was low? What was HRV when I got hurt or sick? Etc. I ended up with 6 months of data of pre-planned training. I discussed my observations in this article.
Basically, I learned that with some simple modifications to my daily training plan, I might be able to see some benefits. I’d say the biggest benefit has been being able to back off the training when my body needs it rather than trying to assume. Pre-planned training failed to account for real life incidences that effect training. HRV monitoring also allowed me to better adjust training in response to illness, allowing me to maintain strength better upon return.
A common topic that arises when discussing the applications of HRV among colleagues is the potential psychological effects. What are they? How does this effect performance?
Here are some example scenarios with some brief thoughts;
- HRV score is low and therefore you expect to feel weaker
– In my experience I’m definitely weaker when HRV is well below baseline. But this is often because a well below baseline score happens; after an intense workout day; when I’m ill; when I perform a very different workout than I’m used to. I’ve found that moderately below baseline scores don’t typically affect my strength. This may be different for you or your athletes. The simple solution would be to keep yourself or athlete blind from the HRV score for an observation period and see what you learn. However, the idea that HRV score can impact how you will perceive training is very real.
- HRV score is high and therefore you expect to feel stronger
– I can’t say that I’m stronger than normal when HRV is above baseline. But I’m certainly not weaker. This again should be tested during an observation period where the trainee is uninformed of HRV score. I must admit that upon seeing a good HRV score I immediately get excited. As if I have permission to train hard. Obviously my perceptions are influenced by my HRV score (based on my previous observations). We probably don’t want this happening with athletes. A good test for me might be to do another observation period. With what I know now about HRV I’m no longer impartial. Perhaps in the future I will test HRV blind for a month or two and see what happens.
- HRV score doesn’t appear to make sense – something’s wrong with me, or the device
– Something may be wrong with you or the device. Or, something may be wrong or inconsistent with your measuring procedure (position, you didn’t go to the bathroom first, disturbed measurement, etc). Additionally, you must consider all of the other factors that affect HRV. I wrote a post on many of these factors here. In short, you must factor in daily nutrition, training load, familiarity of training session, travel, caffeine intake, mental stress, etc. It isn’t just training load that can impact your HRV score.
– Trouble shooting ideas: Check your pulse (on wrist) while recording the measurement to make sure the animated heart is in fact in synch with yours. Make sure the valid pulse indicator is green during the measurement. Make sure that you follow the breathing prompts consistently every measurement (This must be the same every time). Take several measurements in a row. If you do this keep in mind that successive measurements will change slightly (a few bpm and a few points on HRV) but they should be in the same ball park. Be careful when interpreting successive measurements. I find that I get a bit impatient/anxious when recording several in a row which will obviously effect HR.
– If you measure standing (my preferred position) give yourself a minute to stabilize and let your heart rate adjust. Typically upon standing HR will jump up real high to account for the change in blood distribution requirements followed by a marked drop and then an evening out where it comes back up a bit. It may look something like this;
Lying down HR = 51
Standing HR (immediately after standing) = peaks at 102
Standing HR (after several seconds) =drops to 54
Standing HR (once stabilized) = 60
*These figures were made up based on what I recall from performing these tests
- HRV score is low and therefore I might get hurt/perform terribly
– One must keep in mind that come game day, athletes are typically experiencing some form of anxiety. This can be good or bad. Either way it can have a pretty big impact on HRV score that morning which will likely provide a skewed result. Therefore, game day measurements should probably be interpreted with caution. I’d prefer to keep the score from the individual so that it doesn’t mess with their head. Rate performance over time and see how it matches up with HRV. Studies have been done that have looked at this that I’ve discussed in several other posts. See what you find and how it compares. If you do please let me know what you find!
- HRV score is low and therefore I’m overreaching, overtraining, etc
– Again, all other factors must be considered when a score is analyzed. Probably the easiest measurement you can do to determine if one is in fact overreaching is to have them perform some performance tests like a vertical jump or grip strength. Additionally, assess their workout cards to see if their numbers are declining. If they are in fact over doing it performance will decrease with HRV.
For the individual trainee: My best advice that I can give individuals who have an HRV device is to put yourself through an observation period. Try and measure your HRV blind and proceed with your normal pre-planned training routine (or whatever you typically do without the guidance of HRV). Try and document important events that may have effects scores in the “comments section” and keep a training log. It’s hard to analyze data based purely on memory. Having background knowledge of HRV before you use is it can be a blessing and a curse. You’ll likely have expectations or may already be impartial.
For monitoring athletes: In team sport athletes, the less they know about HRV the better (in my opinion). If they can simply take their measurements and forward you the data that is all they need to know and do. If you can somehow manage to have them measure without seeing HRV score then that would probably be best. This will remove the psychological effects that can potentially occur.
In smaller teams and individual sports, this comes down to a judgement call based on your relationship with the athlete and their personalities. By the athlete knowing what their HRV means, how their lifestyle affects it and so forth, you may be able to get more “buy-in” to your program, guidelines, etc. Individual athletes are typically different than team sport athletes. An individual sport athlete typically takes more initiative, holds themselves more accountable, etc. They may respond to it by taking better care of their nutrition, sleep, reducing overall stress, performing active recovery and restoration modalities etc. The alternative would be to keep them vaguely informed and approach them the same way as the team sport athlete.
What’s your take on the psychological issues associated with HRV? What observations have you made? I’d like to hear about them. Let me know in the comments below or via e-mail email@example.com
In 2011, I spent 6 months tracking my HRV with a Suunto T6d watch, software from Firstbeat and from Kubios. The idea was to evaluate HRV change over the period while adding in a reasonable amount of exercise. So I wasn’t trying to make day-to-day changes to volume, intensity, or whether or not to train, but rather to determine the effects over time.
Very cool, Tim. Did you make any observations worth sharing? Did HRV appear to reflect your perceived levels of fatigue from the exercise? Or perceived levels of stress from non-exercise related sources?
I wrote a background post about health and HRV here: http://myathleticlife.com/2011/09/do-you-have-a-healthy-heart/
And I also documented my monthly measurements here: http://soiltosustenance.wordpress.com/2011/07/14/heart-rate-variability-%E2%80%93-june-measurements/ (this one is the last month, but I link to the previous ones if you are interested).
re: Exercise and fatigue – absolutely. I definitely saw the effects on particularly hard days of training. With respect to stress, things were going well during that period of time, so I did see too much of an effect there.
Thanks, Tim, I’ll definitely have a look.