HRV for Recovery Monitoring
More on HRV! How can I measure this myself? First, to recap: what is HRV? Your heart doesn't always beat at a constant frequency and there are small variations between beats. HRV is another term to describe variations in the intervals between heartbeats. Your rate of recovery is dependent on a number of variables, not just the intensity of your workout. How well you sleep, what you eat, your normal daily activities, and training levels all play a huge factor in recovery. Daily HRV measurements are thought to be an indication of how ready your body is to train.
A higher rate of variability indicates that your heart is reacting well to the changes in your body. Persistently low HRV values can indicate chronic stress or overtraining. Measurements taken at the same time daily are the closest to each individual's baseline and can identify trends in variation. Measurements should always be assessed on an individual basis, as each person has their own unique heartbeat and responses to daily life stressors.
So what’s the best way to measure your HRV? I picked 2 highly rated apps to test: Welltory and HRV4Training. Both app use the camera on your phone to take a daily measurement. The camera and light allow the app to use a technique called photoplethysmography (PPG) which illuminates the skin and measures changes in light absorption. Here are my thoughts. Welltory is very user friendly and breaks down your HRV into different areas like Energy, Stress, and Performance (which represents your total HRV). These basic measurements are taken using your iPhone's rear-facing camera. However, more precise measurements can be obtained with a heart rate monitor. Welltory is free to use for basic measurements but a paid subscription will give you a more detailed breakdown of your measurements.
My takeaway from this app is that it's easy to use and great if you're looking for HRV to guide but not dictate your training. HRV4Training is similar to Welltory in that it uses your phone’s camera to take PPG measurements. Additionally, it links to Strava and allows for subjective input on how you feel from the previous day's activity. The app uses a 30-day rolling scale to provide information as it relates to your baseline value. Each daily measurement is followed with a short questionnaire which includes subjective measurements of sleep quality, muscle soreness, perceived exertion the day before, and changes to diet or alcohol consumption. The app then gives you daily advice based on your subjective comments and measurements to help adjust your training. After using the app for a period of time it can provide you with more advanced insight features relating to training intensity, recovery, and performance.
Overall, both of these apps are great for those who like to track their workouts and recovery. What I liked more about HRV4Training is that it uses your subjective reports, in addition to your HRV number, to tailor its recommendation. For example, following a night of poor sleep my recommendation was “your HRV is within your normal values. However, your subjective scores are trending negatively. It might be a good idea to limit intensity today”.
Whatever app you chose to use, remember that HRV is just another tool to aid in your recovery process. Even if your numbers are great and you’re given the green light to train, but you feel terrible, then take the rest day and get back on track tomorrow. Listen to your body first and foremost. Rest days are not punishment or a set back but a chance for your body to reset and recovery properly!
Lisbeth Hoyt PT, DPT, CSCS