You can customize the number of warmup sets and whether you want them for compound exercises, isolation exercises, or both. Here's how:
Tap the Fitness Plan and go to Advanced Settings.
Tap Warmup Sets.
Enable or disable them and/or adjust the number of warmup sets for compound and isolation exercises ranging from 0 to 4.
Keep in mind that you'll get warmup sets for the first exercise of each muscle group in your workout. For example, if you have a workout with Dumbbell bench press followed by Dumbbell flies, you'll only get warmup sets for the Bench press. Same goes for the next muscle group.