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Tracking Heart Rate Variability to Help Manage Client Stress

Josh Elsesser
Josh Elsesser
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Stress is one of the major contributing factors to over 60% of all human illness and disease1. So it’s not surprising that stress is also preventing your personal training clients from achieving the results that they are working so hard for.Stress is such a major deal that NASM devotes a sizable part of their Wellness Coach Certification course to managing it (check out the curriculum here).

In fact, stress can wreak havoc on your clients’ bodies, slowing metabolism, creating hormonal dysfunction, and reducing their ability to make good choices, especially concerning food2.

To better understand the role that stress is having on your clients, we must first define stress itself, the various factors that contribute to it, and the role it plays in maintaining homeostasis.

What is Homeostasis?

Stress Defined

If I asked you to define stress, what would you say? Most people think of stress as primarily mental. Work and life stress seems to be the most common thoughts when the subject is brought up.

However, in terms of the human body, and more importantly for the purpose of this article, in the context of training and fitness, stress is more accurately defined as “anything that disrupts homestasis.”

That can sound like a pretty broad definition, but it is important to note that stress is more than work and family pressure. It is environmental and physical as well. Our bodies are always trying to maintain homeostasis, but when our body encounters a stressor, whether that is a deadline at work, or a car accident, we respond with the same physiological response.

That response, identified back in the 1930s by a ground-breaking researcher named Hans Selye, prepares our body to meet the immediate physical demands of that stressor by rapidly increasing heart rate, blood pressure, and various hormones such as adrenaline and cortisol4.

Stress is also non-specific. Meaning that regardless of the particular stressor, the pattern of the stress response remains largely the same. So whether your client is lifting weights, or experiencing interrupted sleep from anxiety, they will have the same hormones rise, and the same systematic response to deal with that stressor.

This can all seem to become pretty overwhelming for you as the fitness professional. Not to mention what it feels like for your clients. So the big question becomes, “How can I help my clients better manage the stress that is sabotaging their results without completely transforming their entire life?”

Read more: The Symptoms and Effects of Stress

Heart Rate Variability to the Rescue

Right now you may be asking yourself, “What the heck is heart rate variability?” You may have even heard of it. But I bet you didn’t know just how easy it is to use, and how much it can help your client’s programs.

Heart rate variability (HRV) is the change in time between successive heart beats. HRV identifies the activation of the autonomic nervous system (ANS), the part of the central nervous system (CNS) that regulates key involuntary functions of the body, including the activity of the heart muscle; the smooth muscles, including the muscles of the intestinal tract; and the glands. The ANS is broken down into two additional systems; the sympathetic nervous system (SNS), which stimulates the body’s “fight or flight” system, and the parasympathetic nervous system (PNS), which stimulates the body’s “rest and digest” response5. A high variability indicates PNS stimulation, while a low variability indicates SNS activation. It is important to know that extremes in either direction are indicative of some form of excess stress response.

Although heart rate had been measured by the early Greeks, it wasn’t until the 1970s with the advent of digital monitoring devices, that HRV could be effectively measured6. At this time, measurements of HRV began to be used to identify changes in health relating to stress.

HRV is a very easy-to-use, non-invasive, and self-administered assessment that your clients can do while still lying in bed in the morning. All that is required is a heart rate monitor chest strap and a downloadable app that measures their HRV.

In the context of using HRV to better assist our clients’ results, we can use this simple measurement tool to identify the effect that all forms of stress is having on their body, and begin to adjust their training accordingly.

Daily Readiness and Program Design

There are a number of apps available that allow you to monitor your client’s HRV. Bioforce HRV and Elite HRV are two that I have personally used. Both apps provide a Daily Readiness score based on the HRV reading done first thing in the morning upon waking. The Daily Readiness score is a number from 1-10 which indicates the “readiness” of your clients’ body for intense training. The higher the score, the better your client is recovering from her training, and all other stressors she is experiencing. The lower the score, the worse she is recovering, and additional adjustments may need to be made to ensure she doesn’t begin overtraining, or worse, get injured.

When your client is not recovering well, many body processes, such as fuel utilization and hormone production are disrupted. Although they may not experience any adverse effects of this in the short term, long-term under-recovery can lead to serious illness.

By knowing how your client’s body is responding to stress you have new insight into how to train them effectively. Consider this example.

Let’s say its Monday, and you have an intense leg-day session scheduled for your client. However, your client didn’t sleep well the night before, and they are dealing with some heavy work demands. Without HRV, you would have no idea as to the state of recovery or readiness that their body is in. You would go ahead with that leg session, and they may even under perform from how they normally do. On the other hand, had they taken their Daily Readiness score, and it came back low, such as a 3, you would know ahead of time that their body is not recovering well, and therefore should not train at the high intensity that was planned.

The beauty here is that we can modify our clients programs on a day-to-day basis, based on what their body needs. If they have a high HRV score, then its business as planned. But if they score lower, we have the option to reduce the overall stress placed on them during the session. We can reduce the overall load or volume, increase the rest period, or maybe even opt for a low-intensity cardio session.

Assess. Don’t Guess.

As with any technology, HRV is only as good as it is applied. Taking HRV scores but doing nothing different is a waste of time. However, when HRV is assessed, then much of the guess-work of your program design can be replaced by data that can help you to better serve your clients.


  1. https://www.stress.org/stress-is-killing-you/
  2. Segerstrom, Suzanne C., and Lise Solberg Nes. "Heart rate variability reflects self-regulatory strength, effort, and fatigue."Psychological science 3 (2007): 275-281.
  3. Jamieson, Joel. “The Ultimate Guide to HRV Training.” 2012.
  4. Selye, Hans. “The Evolution of the Stress Concept: The Originator of the Concept Traces Its Development from the Discovery in 1936 of the Alarm Reaction to Modern Therapeutic Applications of Syntoxic and Catatoxic Hormones.”American Scientist, vol. 61, no. 6, 1973, pp. 692–699., www.jstor.org/stable/27844072.
  5. McCorry, Laurie Kelly. "Physiology of the autonomic nervous system."American journal of pharmaceutical education 4 (2007): 78.
  6. Billman, George E. “Heart Rate Variability – A Historical Perspective.”Frontiers in Physiology 2 (2011): 86. PMC. Web. 24 Mar. 2017.

The Author

Josh Elsesser

Josh Elsesser

Josh Elsesser is a passionate, dedicated Fitness Professional with 20 years of experience in the Industry. He holds multiple certifications from NASM including: Master Trainer CES, PES, and BCS. He currently owns Kinetic Strength, a corrective exercise and metabolic conditioning company in Southern California. He is also one of the founders of The Mastermind Project, a collaboration of successful Professional Fitness Coaches that are dedicated to providing business and professional development to trainers.


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