Temple's heart rate claim rests on a study the company ran itself

Buyers paying ₹85,000 for the device are being asked to trust a company-run result. No independent lab has tested the claim, and first shipments are not due until early 2027. If it holds, a head-worn optical sensor could give athletes another option in the high-intensity zones where wrist devices struggle. If it fails, the launch loses its main selling point.

What Temple claims

Deepinder Goyal posted the claim on X on 1 November, hours before pre-orders opened. He said accurate tracking is not a solved problem. "You would think accurate HR (Heart Rate) tracking is a solved problem. It is not. Especially in zones 4 & 5, which matter to professional athletes the most," he wrote.

Temple says its device recorded the lowest heart rate measurement error at rest and across five exercise zones. The comparison covered the Apple Watch Series 12, Garmin Forerunner 970, Fitbit Air, Whoop MG and Oura Ring 5. The Apple Watch Series 12 came closest, the company says. Goyal credits two design choices: an adhesive that keeps the sensor on the skin, and placement at the temple, over a major artery. "Temple uses adhesive, so its lab condition is its wear condition. You'll experience our study outcomes in real life," he said.

Temple sells the device as a wellness monitor rather than a medical one. It uses optical sensors the company calls BrainFlow and produces an Entropy score from 1 to 250. The target is elite athletes, starting with heart rate.

How the test was run

The reference device was a Polar H10 chest strap. Temple taped it to the chest because the usual placement can lose contact during sprints and miss heartbeats.

The study was single-site, in Gurugram, with one session per participant and treadmill running only. Cycling, strength training, outdoor running and everyday activity were not tested. Tech Insider said sample sizes and beats-per-minute error figures were not disclosed.

Temple says the full paper and data are on its website. It also says the device beat an untaped Polar H10 in zones 4 and 5. Tech Insider noted that a claim about hard exercise is narrower than a general accuracy claim.

What happens next

Temple says independent researchers are running an extended study. It has invited replication and offered to fund it. Until those results appear, the claim remains a company result.