“I originally started running with a vivoactive 3 music but got frustrated with the touch screen which doesn't particularly work well when it is wet which is a bit of a problem here in Ireland where seems to rain a lot
In my opinion, the 645 is a far superior running watch because of the physical buttons it also has many advanced features runners will find it helpful to monitor progress and train. One Downside, however, is an order to get the most out of the Watch it needs to be paired with an external heart rate monitor the onboard optical heart rate monitor can struggle especially when doing intervals but for day-to-day monitoring it is fine.”
