The Garmin vívoactive 4 and 4S GPS Watch Series is an update to the vívoactive 3 smartwatch. Both of these new watches offer a breathing monitor you can use during yoga workouts. This is pretty impressive considering they don’t even need a chest strap to do so. The only difference between the 4 and 4S is their measurements. The 4S has a 40 mm case size, and the 4 has a 45 mm case size. Unlike the previous version of this activity tracker, these GPS watches now include music features. So you don’t have to purchase a special version for that. And of course, there are all the other features that make an activity-tracking watch like this desireable. These watches can show you step-by-step workouts. So you don’t have to write them down yourself and forget how to do them. With these smartwatches, you get a visual.