BunkerFit Chest Strap Heart Rate Monitor

Train smarter, not just harder.

Most people train in one flat middle gear and wonder why nothing changes. Heart rate is the fix, but only if the number is real. Wrist sensors lose the signal exactly when it matters: heavy sets, cold hands, sprint starts, anything with grip. The BunkerFit BF831 sits on your chest and reads the electrical signal directly, the same method athletes and labs rely on.

Strap it under the pectorals, wet the two electrode pads, open the BunkerFit app and start. You get live beat-by-beat heart rate, your zones and your session history, so easy days stay genuinely easy and hard days actually go hard.

Works with what you already train on

Bluetooth pairing covers the BunkerFit app and any app that supports a Bluetooth heart rate strap, including Strava, Zwift, Wahoo, Peloton and most running apps. ANT+ covers Garmin watches, bike computers and compatible gym cardio machines. Note that most smartphones do not include ANT+, so on a phone the BF831 connects over Bluetooth.

Built for the way Indians actually train

Gym floors, 5 a.m. runs, obstacle races, HYROX-style circuits, football on a Sunday. 48 g of hardware, a strap you can hand-wash, and a battery you replace yourself for the price of a chai.