# CMF Watch 3 Pro review: heart-rate tracking tested on World Heart Day 2026-09-29T05:37:00+00:00 | Technology | Indian Opinion Desk Corroboration: 1 independent outlet Nothing's sub-brand CMF launched the Watch 3 Pro at Rs 7,999 in India, featuring a new optical heart-rate sensor that the company claims is up to 7% more accurate during activity and 3.6% more accurate at rest than previous models. The 1.43-inch AMOLED watch includes dual-band GPS, 131 sports modes, sleep tracking, SpO₂ monitoring, and a 350mAh battery. In testing, the heart-rate readings were similar to those from a pulse oximeter, and the GPS locked within seconds. Sleep tracking distinguished between REM and deep sleep stages, while the Activity Score converts heart-rate data into a daily measure over a seven-day view. CMF states all health features are for personal reference only, not medical diagnosis. ## Indian Opinion Analysis The smartwatch market at this price point is crowded, with the Samsung Galaxy Fit3 and Xiaomi Smart Band 9 Pro both offering heart-rate and SpO₂ tracking for around Rs 5,000-9,000. Mint's reviewer found CMF's optical sensor comparable to a pulse oximeter, which is a consumer device, not clinical-grade, the company's own disclaimer bars medical use. World Heart Day is an awareness event, not a regulatory deadline. The real benchmark will be long-term reliability: the Bureau of Indian Standards has no specific smartwatch accuracy standard, so any claim of improved tracking is self-reported by the manufacturer. Buyers should check the Nothing X app data consistency over weeks, not days. ## Coverage - livemint.com Tags: CMF, Nothing, Watch 3 Pro, World Heart Day Canonical: https://indianopinion.org/cmf-watch-3-pro-review-heart-rate-tracking-tested-on-world-heart-day/ License: Summary and commentary (c) Indian Opinion, reusable with attribution. Facts belong to the linked sources. Cite: https://indianopinion.org/cmf-watch-3-pro-review-heart-rate-tracking-tested-on-world-heart-day/#story-in-brief