For a number of years I've used a Fitbit to track fundamental data to keep an eye on physical performance while hiking. The Fitbit has gone to the great Dashboard in the sky (doffing cap) and I need to replace it. I would like to get a heart rate monitor in the next performance monitoring widget, but reading the wrist type are not nearly as accurate as chest strap types and was curious if anyone uses a heart rate monitor during their hikes for performance monitoring and if so, what type (watch, arm band, or chest strap) and if it can be monitored in real time versus downloading data. I am leaning toward a chest strap type but not getting a clear picture on real time monitoring with an iPhone.

Anyone use these type of devices?