Zach Friedenreich, PT, DPT
Physical Therapist, New York City
Wearable devices are everywhere. From Apple Watches, to FitBits, to Garmin watches and beyond, we have constant access to our physical activity and health related information. Previously, this information may have only been available through a laboratory setting. What can we do with all of this information? Does any of it really matter at all? Stay tuned and we will explore how you can better leverage your wearable device data to stay active and healthy.
What Qualifies As A Wearable Device?
In today’s day and age, you may not even realize that you have a wearable device collecting your physical activity and health information (in the least creepy way possible). What I mean in saying that is you don’t necessarily have to have an Apple Watch, FitBit, or Whoop strap on your wrist to have this information at your fingertips.
Almost every single person carries a smart phone with them throughout the day. A smart phone counts as a wearable device and fitness tracker as well! Our phones can track metrics including, but not limited to, steps, distance traveled, hours spent standing versus sitting, and can record workouts.
If you do have the luxury of owning a wrist-based device, the breadth of data that you have at your disposable is increased significantly; this is mainly due to the ability of these devices to record your heart rate. Heart rate tracking opens up calories burned, VO2 Max estimates, and more complex measures of recovery and workload management. The sky really is the limit in terms of stored data, but how can the regular person practically use it?
Using Your Activity Data
Well, it’s great that your smart devices can record all of this information, but what can you actually use it for? Listed below are the most useful applications of your wearable data for the average joe:
- Basic heart rate tracking during physical activity
- Tracking fitness progress over time
- Monitoring recovery from physical activity
The remainder of this blog post will discuss each of these categories in greater depth.
Basic Heart Rate Tracking
Heart rate tracking is really the basis for much of the application of your wearable data. Tracking your resting heart rate, or the number of beats in a minute while you are not performing any activity, can provide you with information regarding your current fitness level, your sleep quality from the previous night, and current stress levels. Poor quality of sleep and high levels of stress can cause your resting heart rate to be elevated.
When you are exercising, especially during any form of cardio or HIIT, monitoring your heart rate on your wearable device can help you stay within certain training zones. For example, you can subtract your age from 220 to estimate your maximum heart rate. Then, you can calculate percentages of this maximum heart rate to determine whether you are exercising in zone 1 (very light activity, 50-60% of your max heart rate) versus zone 5 (very hard activity, 90+% of your max heart rate).
Tracking Fitness Progress
You can also use your heart rate while exercising to determine and track your level of fitness. After finishing a set of an intense resistance or cardiovascular exercise, measuring the time it takes for your heart rate to return to its baseline level can provide an idea as to your current fitness level. The faster the return to baseline, the more in-shape you are!
In addition to showing you your basic heart rate information, your wearable device is likely using this heart rate information to calculate something called your Vo2 Max. Very simply put, your Vo2 Max is the amount of oxygen that your body can transport to your muscles while exercising at peak intensity. The higher your Vo2 Max, the stronger your level of fitness. Therefore, you can track this number over time to determine whether or not your fitness is improving, staying stagnant, or declining (which you’re hopefully avoiding!!).
Monitoring Recovery From Physical Activity
In my opinion, this is one of the most impactful applications of our wearables and can play a role in reducing our risk of injury if applied correctly. There are two main ways that the quality of our recovery can be assessed: the first goes back to resting heart rate, which we touched on earlier, and the second uses a concept called Heart Rate Variability (HRV).
Your resting heart rate can do a good enough job at supplying some basic insight into your recovery. If you have had a few consecutive days of intense exercise without rest, have been lacking in sleep, have made some poor nutrition and hydration choices (maybe a bit too much alcohol on a Friday night 😉), or all of the above, your resting heart rate may be elevated from your norm.
Similar to the Vo2 Max calculation that we discussed previously, your smart phone or smart watch may be automatically calculating something called Heart Rate Variability. HRV is a much more complex biometric compared to resting heart rate. In essence, it is a measure of the variation in the time between beats of your heart and can also provide insight into the level of recovery that we have achieved. Similar to your resting heart rate, your HRV can be influenced by your training, lifestyle factors (nutrition, sleep, alcohol consumption, stress, etc.), and other biological factors (age, gender, other health conditions). A low HRV may mean that your body is working hard for another reason besides physical activity and may need some time to recover.
When using your wearable device to determine whether your body may need some rest, it is essential to look at the trends over time instead of single day. For example, if you notice that your resting heart rate is steadily increasing over the course of the week or your HRV is steadily decreasing over the course of the week, it may mean that your body is craving some recovery. Recognizing this trend is important to ensure that you provide your body with the rest, recovery, and smart lifestyle choices that it may need. Failing to heed this warning may increase your risk for picking up an injury.
Although that Apple Watch, Garmin, or FitBit on your wrist may be a nice accessory, they are collecting tons of valuable data that you can use to your advantage. The information from these devices can be used to better inform your training, provide an objective way to track your fitness, and let you know when you may need a day or two of recovery. In addition, this information can assist you in making the best possible lifestyle choices to stay healthy, injury-free, and performing at your best! Need some more guidance on using this information to guide your physical activity? We’re here for you!