Apple Watch Series 12 and Ultra 4 add a new Theater Mode setting

The new Health Sensing System in Apple Watch Series 12 and Ultra 4 measures heart rate every five seconds instead of every five minutes, so the green sensor light is almost always flashing. Theater Mode and Sleep Mode revert to five-minute intervals, but a new toggle under Settings > Heart can restore continuous measurements in Theater Mode.

• Heart rate is measured every 5 seconds, up from every 5 minutes on older models
• Theater Mode and Sleep Mode drop back to 5-minute intervals
• A new "In Theater Mode" toggle under Settings > Heart restores frequent readings
• The green light may be visible if the band is worn loosely