Testing HRV with iThlete

The Finger Sensor (uses the headphone jack)

At the behest of one of the athletes I coach who works for Inside Tracker (I will soon be trying this as well), I started testing heart rate variability (HRV) on a daily basis. My athlete had been sending me a daily HRV update. He is a data guy, loves knowing his numbers, especially the finer, more secret points. Thus he had been testing his body daily using a finger sensor (pictured), and asking for adjustments based upon his current HRV. Naturally, the test sparked an HRV conversation, and since I am natural curious and am also looking to understand another tool of the trade, he convinced me to try it and now I too use HRV.

HRV measures the variability of your heart rate while breathing at a slow, even pace. While I am not clear on each factor in the measurement, essentially by using a finger sensor or chest strap and breathing at a selected pace for around a minute, HRV is established as the sensor looks for changes in beat to beat timing. A number is established and after around a week a baseline is established. The best time to collect data is when you wake up, thus you have a consistent measurement.

My HRV

So why is this factor important and why can be garnered from this number? First, when you are rested your number goes up, meaning your body has recovered and might therefore be ready to spring into action. When you are not rested—say after a hard workout—your number drops. I raced a 15k and my HRV dropped 15 data points the next day. My legs felt much the same, but it is nice to have an indicator. Thus the HRV allows you to tweak your week and alter things here and there based upon the active information given by your body. This is more than just heavy legs feeling, this data gives one a more informed feeling, one where you feel more confident altering your plan or alerting your coach.

Testing Screenshot

So what is the cost? While more than one place exists, I use iThlete. You will have to make two purchases in the matter, the app which costs around $8.00, and your choice of a sensor, which will set you back $60-$70. Either way, the data collection is immense, especially as you rate the various factors in your life that contributed to the rise and fall of your HRV, from training load to sleep to mood to diet to stress. While it may not be for everyone, it can lead to a healthier training pattern. If you have questions, ask away.