Headphones with a heart rate monitor

Pulse sensor

— in headphones, the heart rate sensor is placed on the inner surface of the earbud that touches the ear; accurate readings depend on choosing the right eartip size and a snug fit. It’s used to monitor load during everyday runs, gym sessions, bike rides, and trekking, when it’s more convenient to rely on a single gadget. It’s relevant for anyone training by heart rate zones who wants data sent straight to a fitness app without extra devices. Compared to the wrist, the ear provides a more stable contact when things get bumpy. Example use: a 10 km tempo run while holding a target zone, or interval workouts where the headphones tell you when to back off or push harder.