The fitness industry is constantly changing, but one thing that has remained valuable is knowing your Heart Rate (HR). The human body is constantly utilizing energy in the form of calories to fuel the body, however this energy demand increases as we begin to increase activity, and as a response our HR increases. Using a HR monitor is the best way to know if your level of activity is adequate to meet your next fitness goal.
The past few years have been overloaded with new fitness technology measuring HR with an overwhelming amount of settings, and applications, but the question remains: How accurate are they?
The gold standard of HR monitoring is Electrocardiography (ECG), and this technology is what cardiologists use to determine the condition of a patient's heart. Of course this would not be practical for your average exerciser, however we can use it’s accuracy to determine the accuracy of more common devices.
Fitness trackers can be broken down into 2 major categories.
Heart Rate Chest Strap vs Wrist worn Fitness monitor
Heart Rate Chest Strap
Heart rate chest strap works very similarly to the electrodes used in a ECG Test. The chest strap registers the minute electrical impulses released from the heart during ventricular contractions. Chest straps have been repeatedly the most accurate during rest, moderated intensity, and high intensity.
2. Wrist Worn Fitness Monitor
These have been the latest trend in both fitness, and fashion, however there have been multiple studies that exhibit evidence supporting poor accuracy. The technology used in wrist monitors is called Photoplethysmography (PPG). PPG measures coloration changes that occur within your blood vessels as blood volume increases and decreases during heart beats. Unfortunately as exercise intensity increases, and the heart begins to beat faster, this technology has difficulty registering every beat. Any movement of the watch during exercise will also affect its accuracy, so it is best to be worn snug.
The bottom line is, if you want accuracy choose the chest strap, and if you want a ballpark HR with the benefit of fashion go with the wristband.