Amazfit Cheetah 2 Ultra Review: Best Wrist HR Accuracy at £600

What it is

The Amazfit Cheetah 2 Ultra is a premium trail and road running watch launched in 2026 at £599.90, positioned squarely against Garmin's Forerunner 970 at the same price. It is the step-up sibling to the Cheetah 2 Pro, released just four weeks earlier, and targets serious runners who want accurate GPS tracking, strong optical heart rate performance, and trail-specific features without paying the Garmin or Suunto premium. At this price, Amazfit is no longer playing in the budget-friendly space; this is a direct assault on the mid-to-high performance running watch market.

Key specs

• GPS chipset: Dual-frequency GNSS
• Battery life: 55 hours in GPS mode (projected, not independently confirmed in a live field test)
• Sensors: Wrist optical PPG for heart rate and HRV, SpO2 (blood oxygen via optical sensor), SmO2 (muscle oxygen saturation), barometric altimeter
• Display: Not confirmed in available sources
• Water resistance: Not confirmed in available sources
• Weight: Not confirmed in available sources

Performance in the real world

Let's start with GPS, because that is what trail runners care about most. On a standardised 10-mile GPS accuracy test, the Cheetah 2 Ultra scored 81%. That is a genuine improvement over the Cheetah 2 Pro's 73%, but it still trails the Garmin Forerunner 970 at the same £599.90 price point. In a separate trail-specific test, the score climbed to 85%, which suggests the dual-frequency GNSS performs better in complex, tree-canopied environments than on open roads. That is a meaningful finding for the target buyer. Still, if GPS accuracy is your single non-negotiable priority and you run in challenging terrain, the Forerunner 970 edges it.

Heart rate accuracy is where the Cheetah 2 Ultra genuinely impresses. Across multiple independent tests, this watch delivered five excellent results from six sessions, including a HYROX simulation in a 33 degree Celsius gym environment. In that test, the wrist optical PPG sensor showed near-zero bias against three separate reference devices: the Whoop MG worn on the biceps, the Garmin HRM-600 chest strap (which detects electrical impulses via ECG), and the Polar Verity Sense optical armband. In a road bike sprint test, the Cheetah 2 Ultra returned limits of agreement of plus or minus 3 bpm, compared to plus or minus 6 bpm for the Fitbit Air in the same test. That is a clear, data-backed win. A separate HYROX comparison also placed the Cheetah 2 Ultra essentially tied with the Whoop MG on accuracy, which is high praise when the Whoop MG is worn in an optimal position on the bicep.

The SmO2 sensor is worth flagging. Muscle oxygen saturation monitoring at this price tier is uncommon and could be useful for altitude training or high-intensity interval work. The sources confirm its presence, though published data on its accuracy or real-world utility beyond acknowledgement of the feature remains limited.

Battery life is projected at 55 hours in GPS mode. That covers ultramarathon distances comfortably and is competitive with the Forerunner 970. The 55-hour figure comes from The5kRunner's projection rather than a live multi-day field test, so treat it as directionally accurate rather than confirmed.

The app ecosystem sits on Zepp OS. It has improved significantly over the past two years, but it remains behind Garmin Connect in depth of training analytics, third-party integrations, and the breadth of structured workout options. If you are deep in the Garmin ecosystem or rely on Garmin's Connect IQ apps, switching carries a real cost.

Who it's for / who should skip it

The Cheetah 2 Ultra is built for trail and road runners who want serious optical HR accuracy, solid dual-frequency GPS, and 55 hours of battery life without committing to the Garmin price premium for equivalent hardware. If you are upgrading from a mid-range Amazfit or a basic Garmin and want performance data you can actually trust, this delivers.

Skip it if GPS accuracy at the absolute top of the market is your priority. The Forerunner 970 at the same price scores higher on GPS tests. Skip it also if you are embedded in the Garmin or Apple ecosystem, or if you rely on third-party running apps that integrate tightly with Garmin Connect or Apple Health. The Zepp OS platform is capable but not class-leading for analytics depth.

The Cheetah 2 Pro buyer also deserves a direct answer: the Ultra costs £150 more, improves GPS accuracy from 73% to 85% in trail conditions, adds the SmO2 sensor, and delivers stronger heart rate results. If you run trails regularly, that £150 gap is probably justified. If you run roads and parks, the Pro gets you most of the way there for less.

Verdict

The Amazfit Cheetah 2 Ultra is the most accurate optical heart rate monitor in its price class right now, and its trail GPS performance is genuinely competitive. It does not beat the Forerunner 970 on GPS, and the Zepp OS ecosystem still has ground to cover against Garmin. At £599.90, it earns its place as a serious option, but only if heart rate accuracy and battery life matter more to you than GPS precision and app depth.