HRV as an Assessment Tool

by Elite HRV | application, Blog, Health, performance

Assessments and Heart Rate Variability

In our clinic, we believe that when working with clients – if you can’t measure it, you can’t manage it. We use many objective measures to make sure our treatment plan is producing the response we need and to allow the patient to have continuous, objective feedback to their progress.

There are thousands of tests and assessments that can be used to determine the current status of our health and performance. Functional Movement Screen, total cholesterol, blood glucose, MRI’s, Vitamin D levels, VO₂max, 1 rep maximum, anaerobic threshold and the list goes on.

There are thousands of tests and assessments that can be used to determine the current status of our health and performance.

We use some of the above tests in our clinic, as well as additional physiological assessments to test clients’ ability to use their respiratory, circulatory and muscular systems in both a rested and an active state.

We make heavy use of Heart Rate Variability assessments. Regularly assessing our patients’ HRV values helps our clinic in three main ways:

To promote accountability for the client to be a part of the recovery process
To gain an objective understanding of the lifestyle factors affecting the client’s condition the other 99% of the time that they are not with us
To ensure that intervention is having a positive impact on overall health via an increase in HRV

What HRV Can and Can’t Tell You

As an assessment tool, I use HRV to determine if there are any “red flags” that need to be addressed, which is similar to what I use the Functional Movement Screen for to assess movement competency.

I use it to gain a deeper understanding as to what is limiting someone’s potential or to help isolate what seems to be keeping an individual from making progress. This can be the middle-aged woman who has done everything to lose weight but can’t, or someone trying to manage multiple chronic diseases, or to guide physical rehabilitation.

In my clinical experience, I cannot tell you exactly why an HRV value is what it is without additional context.

Heart Rate Variability is a measure of Autonomic Nervous System balance and strength and consequently your systemic health and resilience. Despite the powerful and individualized information HRV can provide about the body’s health, it does not give you specific information as to exactly what to focus on. For example, a low baseline HRV value could be due to overtraining, diabetes, or depression. Which is it? In each case, Heart Rate Variability will likely give a strong indication that something is wrong, but it will not identify the culprit for you.

To effectively determine what is producing the abnormal HRV values, we must add meaningful context. We must take into account the full picture of an individual’s situation as we discuss below in the “how” section.

To effectively determine what is producing the abnormal HRV values, we must add meaningful context. We must take into account the full picture of an individual’s situation.

How to Assess With HRV

Step 0 – Context

Before collecting any objective data and starting an intervention or assessment, you need to establish subjective and qualitative markers to add context to any quantitative data. The combination of qualitative and quantitative data helps establish a much more meaningful baseline, and helps with tracking progress and defining the end goal.

Some examples of contextual data gathered prior to treatment would include wellness questionnaires, family history, lifestyle patterns, and subjective perception of the condition and the end goal.

Step 1 – Form a Baseline

Just like many assessment tools, it is important to establish true baseline values prior to an intervention. This gives you hard data to compare progress to throughout the training or treatment plan and prevents you from blindly guessing the level of progress attained.

Ideally, during a lower stress period, gather 4-5 days within a single week of short-term (under 5 minutes), morning HRV measurements. If you have access to a 24-hour HRV monitoring system, that can also help add additional information. However, it is still important to take several days worth of measurements to ensure that the single day was not an outlier and to increase confidence in the baseline values.

This is also the ideal time to refine which contextual information will be the most helpful for tracking progress. Useful metrics that add context to Heart Rate Variability values include:

Perceived energy levels
Sleep quantity and perceived quality
Exercise quantity, type and perceived exertion
Mood and perceived stress levels

Additionally, you might track other metrics depending on your goals. Blood markers, body weight, blood pressure, and fitness benchmark tests are all examples of common metrics tracked alongside HRV.

Step 2 – Intervention

In this phase, you implement a plan for yourself or your client that addresses the overall health or performance goals and will measurably impact the chosen relevant metrics.

Depending on the starting point and goals, you should expect to see noticeable changes in Heart Rate Variability within 1-3 months for most health related goals and in as little as two weeks for fitness and training related goals.

Depending on the starting point and goals, you should expect to see noticeable changes in Heart Rate Variability within 1-3 months for most health related goals and in as little as two weeks for fitness and training related goals.

Determine an appropriate timeframe for which you would like to see progress. Then, make sure to take at least another 4-5 morning HRV readings the week leading up to your planned milestone.

It is ideal if you are able to take consistent HRV measurements throughout the entire intervention. I recommend that my clients take daily readings throughout. This not only gives you insight into unexpected setbacks or inexplicable jumps in progress, but it also gives a cushion in case a few days of measurements are missed here and there.

Step 3 – Determining Progress

To assess your progress, compare your HRV values to your starting baseline as well as your contextual markers.

The first things to check are goal oriented and subjective markers. Has the situation, or the perception of the situation, improved? Are you making progress towards your goals?

Combining this information with Heart Rate Variability data generally produces the following conclusions (the following assumes that reasonable goals were defined and adequate time/effort has been given):

Progress towards your goals is stagnant or backsliding.

In this case, if HRV has remained the same, then your training or treatment plan is either not effective, and needs altering or not enough time has passed to see progress. This could also indicate that there is potentially some underlying aspect preventing progress and some additional data might need to be gathered at this point to determine if something like hormone imbalance, food sensitivities, psychological stress, etc. are diverting the body’s resources and preventing progress.

If HRV has decreased, this could be a warning sign that either new stressors are present or the plan is causing more harm than good.

If HRV has increased and your goals are health oriented, you may be making underlying progress. Using additional contextual information will help you determine whether to continue or to alter the plan. For exercise and training goals, if subjective measures of motivation and energy levels check out, then you may be increasing your tolerance for the prescribed exercises but may need to alter volume/intensity/type of training to achieve your goals.

Progress has been achieved.

In this case, if HRV has increased, and there are no warnings from other contextual information, congrats! You are likely on your way to achieving your goals and improving your health at the same time.

Conversely, especially with relation to exercise, if subjective measures of energy levels, motivation or mood are negative, the body may actually be reaching an overtrained state and is trying to overcompensate with recovery. Congratulations on your progress but now may be a good time to consider addressing the new state.

If HRV has decreased – this is a tricky situation. Certain goals such as fat loss and exercise programs can cause HRV to temporarily decrease while making progress. The body may be experiencing temporarily elevated stress levels in the pursuit of your goals. The decline in HRV should be monitored to make sure it is a temporary condition and not an early warning sign for a developing issue.

Contextual information such as perceived energy levels, motivation and mood help assess whether the stress is still in acceptable ranges for positive adaptation. If HRV has decreased and other contextual information have also trended negatively, then you must consider the potential that you may be sacrificing health to attain your goals.

Example Uses of Heart Rate Variability

The concept of using HRV as an assessment tool can and has been applied to many situations. The following are a few examples of how HRV can play a role in assessing various scenarios:

Health Conditions. Common health conditions such as weight loss, diabetes and immune system conditions have all been linked with changes in HRV. Even more severe health conditions have seen benefit from HRV assessment. For example, decreased Heart Rate Variability has been linked with an increased likelihood of ischemia and could be used as a non-invasive assessment in place of exercise stress testing for ischemia (Goldkorn et al., 2015).

Common health conditions such as weight loss, diabetes and immune system conditions have all been linked with changes in HRV. Even more severe health conditions have seen benefit from HRV assessment.

HRV has been determined to be an effective assessment of inflammation through the vagus nerve (Huston and Tracey, 2010). Further, inflammation has been strongly linked with metabolic disease (Liao et al., 1998), and HRV may be a useful tool to measure progress when addressing metabolic disease.

Fitness and Performance. Through daily HRV monitoring, you can limit overtraining or sub-optimal progression of a training program (Plews et al., 2012) to ensure that correct load requirements are given to each specific athlete. This allows HRV to be used to guide training sessions (Plews et al., 2014) for maximum progress and efficiency by providing optimal exercise-to-rest ratios during a training cycle. It can also provide an indication of training status and adaptation capabilities to determine someone’s physiological readiness to train. This will give you information about if you have the ability to meet the demands of a high-stress training program, or if there is preliminary work that needs to be implemented in order to perform at the highest level.

Takeaways

Heart Rate Variability is a powerful assessment of the system-wide condition, but needs context to determine the specifics of the situation.

It is ideal to have at least 4-5 days of morning HRV measurements within a single week to establish a confident baseline and to compare future values to the original baseline.

Assessing HRV can help determine if progress is being made on a given plan. In the case of health, increases in HRV are generally desirable. In the case of fitness and training, temporary decreases in HRV should be expected – and the use of context can help determine whether the changes in HRV are acceptable.

Interested in learning more about the science behind HRV and how monitoring it can help improve your health and performance? Get access to the “Foundations of Heart Rate Variability” course in August!

References:

Goldkorn, Ronen, Alexey Naimushin, Nir Shlomo, Ariella Dan, Dan Oieru, Israel Moalem, Eli Rozen, Ilan Gur, Jacob Levitan, David Rosenmann, Yakov Mogilewsky, Robert Klempfner, and Ilan Goldenberg. “Comparison of the Usefulness of Heart Rate Variability Versus Exercise Stress Testing for the Detection of Myocardial Ischemia in Patients Without Known Coronary Artery Disease.” The American Journal of Cardiology 115.11 (2015): 1518-522. Web.

Huston, J. M., and K. J. Tracey. “The Pulse of Inflammation: Heart Rate Variability, the Cholinergic Anti-inflammatory Pathway and Implications for Therapy.” Journal of Internal Medicine 269.1 (2010): 45-53. Web.

Liao, D., R. P. Sloan, W. E. Cascio, A. R. Folsom, A. D. Liese, G. W. Evans, J. Cai, and A. R. Sharrett. “Multiple Metabolic Syndrome Is Associated With Lower Heart Rate Variability: The Atherosclerosis Risk in Communities Study.” Diabetes Care 21.12 (1998): 2116-122. Web.

Plews, Daniel J., Paul B. Laursen, Andrew E. Kilding, and Martin Buchheit. “Heart Rate Variability in Elite Triathletes, Is Variation in Variability the Key to Effective Training? A Case Comparison.” European Journal of Applied Physiology Eur J Appl Physiol 112.11 (2012): 3729-741. Web.

Plews, Daniel J., Paul B. Laursen, Andrew E. Kilding, and Martin Buchheit. “Heart-Rate Variability and Training-Intensity Distribution in Elite Rowers.” International Journal of Sports Physiology and Performance IJSPP 9.6 (2014): 1026-032. Web.