Changes

* '''Heart Rate Variability'''. There is a growing interest in the possibility of using [[Heart Rate Variability]] (HRV) to evaluate training stress. While only one device will display HRV, there are several that will record HRV for later analysis.

* '''GPS Pre-cache'''. Some newer watches will download the predicted positions of the GPS satellites for faster initial acquisition. This pre-cache works remarkably well, and the data is usually downloaded automatically when the watch is connected to the internet. However, the data is only valid for a few days, so after that time the device will fall back to the usual approach of scanning for satellites.

=Using a Smartphone=

''Main article: [[Running With A Smartphone]]''