If you find it uncomfortable to wear chest straps to monitor your heart rate or are wary of using unreliable devices, here is a solution in the form of Fingertip Heart Rate Monitor.
Measuring 2 1/4″ in length, 1 1/4″ in width and 1 1/4″ in height, this device includes two AAA batteries and costs $99.95. You can simply clip this device to your finger, and it will automatically provide an EKG accurate reading to ±2 beats-per-minute. On its 1 1/3″ OLED screen, the reading is displayed in large numbers that are pretty easy to read. You can even use this device to measure your blood’s oxygen saturation (SPO2) without the need of any blood sample or a visit to the doctor.
Since this heart rate monitor can easily fit into your shirt pocket without inhibiting your hand movements or causing any other kind of obtrusion, you can now get your heart rate measured even while you are traveling.