HRV

Heart Rate Variability (HRV) training utilizes today’s available technology to assess a heart metric that can provide valuable information about how a client or athlete can maximize their physical efforts. Similar to Metabolic Efficiency Testing, personal trainers can leverage HRV training to help better grasp client energy level and plan accordingly.

What is Heart Rate Variability?

Through the course of your day, the heart also goes through periods of rest and exertion, receiving blood from the body and pumping freshly oxygenated blood back out–the heartbeat. Your heart rate (HR) refers to how many times your heart beats per minute and can be an indicator of cardiovascular health. HR is also known as pulse, and while a normal heart rate varies from person to person, the healthy range for adults is 60-100 beats per minute (bpm).

Heart Rate Variability (HRV) is a measure of the variation in the time interval between heartbeats. This pause between contractions of the heart muscle can be viewed on an electrocardiogram as the spike in the “R wave,” or the waveform. Any differences in the time between one R wave and the next would be referred to as variations. HRV can be calculated by using the standard deviation of beat-to-beat measurements which are captured by the heart rate sensor.

HRV is different from basic heart rate tracking that measures bpm because it measures the time variance between heartbeats.

Why is HRV relevant to training?

By tracking HRV, you can get a good grasp on the resilience of your heart which can, in turn, serve as a potential predictor of both well-being and longevity. It can also provide valuable insights about how well your body is recovering and how to manage workout intensities (for more than just cardio training). This metric may also be a predictor of altitude sickness, so physiologists use it to evaluate conditions at higher elevations.

How can I measure HRV without sophisticated medical equipment?

HRV can be tracked daily by using an app. Many apps require you use an external heart rate monitor but some use just the smartphone interface to take a measurement for 60 seconds (works on most phones). You’d start by getting a baseline measurement for about four days in a row of using the app to measure your HRV first thing in the morning (at the same time each morning, if possible). The app will calculate the variability between heartbeats.

A solid app will also ask the following  questions, allowing for subjective input:

  1. How was your sleep quality the night before?
  2. How many hours of sleep did you get the night before?
  3. What activity was done yesterday, for how long and its intensity level?
  4. What was the Rate of Perceived Exertion (RPE)?
  5. How well would you rate your performance?
  6. What is your level of motivation to train today?
  7. What is your current physical condition?
  8. What is your level of fatigue this morning?
  9. What is your current level of soreness?
  10. Do you have any current injuries?
  11. How would you rate your lifestyle (does it involve travel and fluctuate or is it relatively routine)?
  12. Where you traveling yesterday?
  13. Are you currently sick?
  14. Did you consume alcohol yesterday?

Some apps allow for additional comments and notes prior to generating your HRV score for the day.

Do note, if you’d like the most accurate measurement, it’s recommended to have the measurement taken at a medical facility through the use of an ECG.

What information will the measurements provide?

After taking HRV measurements consistently for a few days, the app will calculate a ‘healthy’ range and baseline score for the user’s HRV. The app can then be used to take HRV measurements prior to training sessions. If a client or athlete’s HRV falls out of the desirable range (or baseline), the intensity of the day’s training session can be modified (typically it’s decreased). If the HRV falls too far out of the desirable range, it can be beneficial to use that day as recovery or a rest day.

The ranges become important because if the HRV results are out of the baseline range for the user, it’s showing the heart’s current state is not in the most recovered state or prepared for peak performance. Hence, the app suggests to either lower intensity or rest on these days.

Bear in mind that HRV values can generally range from 30 to 120 but apps like HRV4training compute a recovery score based on your input that is in the 7 to 10 range, in order to make meaningful sense of all of your data.

Once a baseline HRV reading is established by regular use of the chosen app, when your body falls within the ideal range, then most likely it is in an unstressed state and less likely to suffer overuse injuries.

How fitness pros can use HRV training apps

Taking a daily HRV measurement can be used by fit pros as an indication of training readiness. Once a baseline reading is established by regular use of the chosen app, if your body falls in the ideal range, it’s most likely that the body is in an unstressed state and is less likely to suffer overuse injuries.

Two of the top-recommended apps on the market are:

  1. EliteHRV
  2. HRV4Training

HRV4Training app has a Pro version that can be used by fit pro’s to track clients (if they chose to).  This innovative app works by reading your finger on your smartphone’s camera lens to track your heart rate based on the color changes on your skin, but will also work with a heart rate chest strap. Having clients take a daily HRV measurement can help personal trainers plan the day’s workout accordingly.

Considerations for HRV training:

HRV training is a great way to gain insights into how well you or your clients are recovering and help manage and vary workout intensities. However, using an app to track HRV does not replace proper medical attention or an ECG as needed.

If a client presents with a current cardiac condition or history of one, extra caution using this technique is recommended along with clearance and coordination with the client’s medical provider. Use care with the choice of HRV app or measuring device used. As fit pros, it’s always prudent to do an assessment for Cardiovascular Risk prior to starting them on any program. 

Taking a daily HRV measurement can be used by fit pro’s as an indication of training readiness. Once a baseline HRV reading is established by regular use of the chosen app, if your body falls in the ideal range, it’s most likely that the body is in an unstressed state and is less likely to suffer overuse injuries.

HRV Training can help to motivate clients whose primary goals may not be hypertrophy, weight loss, or aesthetic. Some clients prioritize functional movement, mobility, or other health-related goals. HRV training can be an alternative, creative way to track heart health for those who are averse to measuring weight. For those with hypertrophy, weight loss, or aesthetic goals, HRV training can be a great addition and added tracking tool! It is also being used by elite athletes to track how well their bodies are recovering from training and to gauge their readiness to go into the next training session.

Certainly, the more we have in our toolbox as professional trainers, the closer we can help our clients to achieving their goals.


References:

https://advancingthescience.mayo.edu/hrv/
https://www.diygenius.com/meditation-and-heart-rate-variability-training/
https://www.mayoclinic.org/healthy-lifestyle/fitness/expert-answers/heart-rate/faq-20057979