Self Monitoring Health & Fitness Levels

By: Hayden Gray, DPT

The Benefits of Tracking Your Health & Fitness Levels

There are so many accessible, and wearable pieces of technology in today’s health market. This is a great thing but can also be overwhelming if you don’t know what certain terms mean or why it might be important to pay attention to them. So first, I’ll define common terms you may see when looking for a wearable fitness device, and then I’ll discuss the ones I feel are the most important.

Resting Heart Rate- The lowest number of beats per minute your heart performed while at rest.

Average Heart Rate- The average amount of beats per minute your heart performed throughout the day. The more you move the higher your average heart rate for the day may be.

Max Heart Rate- The highest amount of beats per minute your heart performed at any point throughout the day. This is most commonly tracked when exercising.

Heart Rate Variability- The change in time intervals between each BEAT the heart performs.

Oxygen Saturation- A percentage of the amount of oxygen currently in the blood.

Maximal Oxygen Consumption- (Also known as the VO2 max) A measure of the amount of oxygen the body can absorb and use during exercise.

Respiratory Rate- The number of breaths that are taken per minute.

Skin Temperature- The temperature of the skin which is typically lower than the “core” temperature.

NOTE: The majority of these readings on a wearable device are average values, some devices provide real time data when exercising.

I frequently monitor my resting heart rate as it is a great indication of how well my heart is supplying my body with oxygen at rest. In a sense, the lower your resting heart rate, the less amount of energy is required to adequately supply the body with oxygen. The typical average resting heart rate is between 55-85 beats per minute, but in many circumstances, athletes and healthy adults have resting heart rates <50 BPM. With that being said, when my resting heart rate falls out of its typical range (45-50 BPM) it could be for a few reasons. One of them being due to multiple days of high intensity training where I’m exercising at 80-90% of my heart rate max. This is a normal response to increased cardiovascular stress and the body’s ability to remove “waste” following breakdown or conversion of byproducts in the body. However, if my resting heart rate is continuing to increase through a training cycle, it might be time for a rest day or a lower intensity day. An increased resting heart rate can also indicate illness, poor sleep, increased caffeine intake, or stress (there are other reasons, but I feel these are important to note). This principle can also be applied to better understanding average heart rate throughout the day.

Secondly, I track my heart rate variability. Like I said above, heart rate variability is the change in the time intervals between each beat the heart performs. The time interval between each heart beat is not the same every time, there is actually a variation of time between each beat. Due to that, HRV varies from person to person and is influenced by age, physical fitness, and the ability to balance the nervous system. To avoid over complicating the already complex nervous system, I’ll highlight two important parts: the sympathetic, and parasympathetic nervous system. The sympathetic nervous system is responsible for readiness, so our ability to respond to stressors such as exercise, or a “threat”. The parasympathetic nervous system is responsible for our ability to relax and unwind. The ability to balance these appropriately plays a major role in our heart rate variability. For example, prior to the gym or exercise, if you find yourself getting excited, more alert, and energized, you are utilizing the effects of the sympathetic nervous system. Following exercise, or any activity, if you are able lower your heart rate, calm your breathing rate, and fall into a relaxed state, you are shifting back into a parasympathetic state. Individuals who feel increased levels of stress, moderate levels of energy, or constantly feel on “edge” have difficulty shifting between these two which could impact their heart rate variability. So having the ability to track this via a wearable device, may help people lower their stress and increase their HRV.

There is another component of a wearable fitness device that I feel is important to keep track of which is SLEEP. Understanding and identifying certain habits that influence sleep is extremely important for living a healthier lifestyle. For example, a wearable fitness device can identify when you fell asleep, how many times you woke up throughout the night, how many hours you were asleep for, and what stage of sleep you spent the most time in (based on heart rate data) and your average heart rate when you sleep. If you woke up multiple times throughout the night, it may be important to document bedtime habits and identify which ones may be impacting your ability to stay asleep or fall asleep.

Lastly, these metrics are great to keep track of and can be used as a tool to guide your training and help you build healthy habits. However, it is easy to get caught up in the way it is displayed to you. Some devices may give you some form of “score” or “rating” that indicates how well you “recovered” or how hard you worked throughout the day. I believe there is some value to that, but it can often lead to developing a negative mindset when you get a “poor score” to start your day. Allow the device to help you build healthy habits and allow it to help you identify what might impact some of those metrics above so you can stay optimal and healthy!