The reviews on this watch were so great that I was confused by the poor performance of the watch. The heart rate sensor is essentially useless, consistently lagging 20-30 bpm and updating slowly and completely uselessly above 170 bpm. Tempo data at the end of the run is generally accurate, but real-time data updates very slowly and is inaccurate. In particular, without accurate heart rate measurements, the rest of the information on the watch is useless. I recommend avoiding this watch and just using a phone GPS tracker and a decent heart rate strap. Usually cheaper and very accurate.
Garmin eTrex 10 Navigator
31 Review
Garmin Forerunner 35 Band Soft Silicone Replacement Watch Strap - Compatible With NotoCity Smartwatch
32 Review
Polar Vantage M Smart Watch, Black
33 Review
Garmin Forerunner 45: Easy-to-Use GPS Running Watch with Free Training Plan Support in Red
21 Review