Capturing HR once a minute is of really limited use. More than benchmarking against resting HR, the interesting thing is to look at heart rate variability, and to do that you need to scan several times per second. For that using purpose-built devices is just better. I am thinking: https://jawbone.com/store/buy/up3 or http://www.getqardio.com/qardiocore-wearable-ecg-ekg-monitor...