Even though HRV science has been around for over a decade, its access has been limited to a select few. Now that companies are making devices that allow for personal use at a reasonable price, it has begun to pick up steam. HRV stands for heart rate variability. The device measures the central nervous system's ability to function and maintain homeostasis. More specifically, the autonomic nervous system’s functioning. The autonomic nervous system controls basic human functions that can be subconscious or conscious (heart rate, blood sugar and blood PH levels are examples). The HRV device utilizes an algorithm that computes a numerical value based on your pulse and RR wave. Based on a person’s cardiovascular fitness and general health, this number will deviate through a range. As you continually take readings, you can start to see where you typically fall on the spectrum. There is a range that you will move through that is considered normal deviation patterns. When you slip out of your normal range, you can start to see the detrimental effects of the stress that is being imposed on the body.
How does this help us in managing our health? In all my years of looking for things to help improve my own abilities, measuring my HRV everyday is the best tool to date in my opinion. In a time where we can get information immediately and are promised results in a blink, this device delivers on both. I think by being able to monitor your own HRV regularly you can understand how your own system responds to the stress the environment/yourself impose on it. It gives you a marker that allows you to fully understand that there are more important things that affect your health, besides the new supplement that media is pushing. It gives a clear idea of what the 3 basic components of health are: nutrition, physical/emotional stress and recovery. These 3 categories have a lot of subcomponents, but in general they are what drives one's ability to survive and progress. I would say the category that gets overlooked the most is recovery. Most people are so focused on the other two that they don't fully understand how much of an impact recovery has on your progress. It doesn't really matter if you work out 5 days a week and eat perfectly; without adequate sleep the body will break down. By monitoring your HRV you can find a sweet spot that will promote progress without requiring constant perfection.
I think an overlooked benefit to monitoring your HRV regularly, is the accountability it instills. Prior to using it I never really had an idea of what effect a bad night's sleep or drinking alcohol had. Now I know that 2 nights of sleeping poorly or 1 night of heavy drinking can drop my HRV considerably. Correlating the number with how I feel makes it easier to now assess whether it's worth having a few more beers or staying up late to watch a movie you’ve seen 5 times.
Over the past 8 months this is what the data has revealed:
1. I can lift about 4-5 days a week without overdoing it. If I push past that, by the end I feel like I got run over by a truck and want to sleep for a few days. I haven't had a major injury in the past year because if my HRV is low, I don't lift. Normally I might try to push past it because "that's the day I squat". It allows me to have a plan, but also make day-to-day decisions that are more tuned to how my body is responding.
2. Light exercise can be done everyday based on your heart rate and it doesn't have a huge effect on your HRV. This means if I bike 6 days in a row, but don't really push myself on intensity, my HRV will not register a change. People that do the same things over and over without changing intensity probably never stress the body enough to adapt. (the first people that come to mind are runners that aren’t training for a specific event).
3. When I was trying to gaining weight for 3 months, which meant lots of extra calories (crappy ones to boot), my average HRV dropped 5 points lower. I also felt very sluggish most of the time. 3 days of good eating usually rights the ship, just as 3 days of bad eating starts to sink it.
4. Sleep started to become my new obsession. If I stayed out late one night and I would wake up expecting the number to be low, but it was only a few points different. Do that another 2 nights and it dropped like a rock.
5. Alcohol kills any chance of lifting or training. My normal HRV range is between 65 and 75 on the Bioforce device. One time I was sick with a fever and couldn't hold any food down. My HRV that day was 34. The next day when I was feeling better, (good enough to eat), it was 55. As I got healthy, it climbed back up to the 70s. After drinking at a wedding and staying out to late, my HRV was 29. I was immobilized all day and could barely form a thought. Drinking excessive alcohol is a lot like causing your system to be sick and a sure fire way to inhibit your ability to perform. I love beer, but it makes me think twice before I have more than 3 now. I find that I can get away with 3 and still be able to lift the next day.
If you really want to take control of your health and also find the quickest path to success, I highly recommend taking a look at HRV devices.