Amazfit Cheetah 2 Ultra Review: Trail Runner's Sleeper Hit

<h2>What it is</h2><p>The Amazfit Cheetah 2 Ultra is a trail and road running watch positioned at £599.90, sitting squarely in the premium GPS sports watch tier. It arrived just four weeks after the Cheetah 2 Pro at £150 more, which immediately raises the obvious question: what does the extra money actually buy? Amazfit is targeting serious runners who want flagship-level accuracy without defaulting to Garmin or Polar, and the Ultra is their clearest attempt yet at that market. The competition at this price is real and named: the Garmin Forerunner 970 sits at the same price point.</p><h2>Key specs</h2><ul><li><strong>GPS chipset:</strong> Dual-frequency GNSS confirmed</li><li><strong>Battery life:</strong> 55-hour GPS battery projection</li><li><strong>Sensors:</strong> Optical PPG heart rate (wrist-based, measures blood volume changes via LED), SpO2 (optical blood oxygen saturation), SmO2 muscle oxygen sensor, barometric altimeter (air pressure-based altitude calculation)</li><li><strong>Display:</strong> Not detailed in sources</li><li><strong>Weight:</strong> Not detailed in sources</li><li><strong>Water resistance:</strong> Not detailed in sources</li></ul><h2>Performance in the real world</h2><p>This is where the Cheetah 2 Ultra earns its keep, and the numbers from structured testing back it up across GPS, heart rate, and cross-activity accuracy.</p><p><strong>GPS accuracy</strong> came in at 81% on a standardised 10-mile test. That is a meaningful jump over the Cheetah 2 Pro's 73% score, and it is the kind of improvement that translates to tighter route traces on winding trails rather than just a number on a spec sheet. The catch: the Forerunner 970 still beats it at the same price. If GPS precision is your single non-negotiable, Garmin still has the edge here. But 81% with dual-frequency GNSS is a legitimate result, not a rounding exercise.</p><p><strong>Heart rate accuracy</strong> is the genuine surprise of this watch. Across multiple structured tests, the Cheetah 2 Ultra's optical PPG sensor returned near-zero bias against reference devices including the Whoop MG and Polar Verity Sense. In a road bike sprint test, limits of agreement came in at approximately plus or minus 3 bpm. In a HYROX simulation run at 33 degrees Celsius, optical HR matched reference devices across all comparisons. Five out of six heart rate sessions were rated Excellent in trail testing. These are strong results by any standard, and they hold up across different activity types and thermal conditions.</p><p>The SmO2 sensor (muscle oxygen saturation) is worth mentioning separately because it is unusual at this price. Muscle oxygen monitoring gives runners an additional layer of training load data beyond standard heart rate and pace, though the practical utility depends heavily on whether the companion app surfaces the data in a usable way.</p><p><strong>Sleep tracking</strong> is not directly tested in the available sources, so no data-backed assessment is possible here. That is a gap worth noting for buyers who weight recovery metrics heavily.</p><p><strong>App ecosystem:</strong> Amazfit runs on its Zepp platform. The sources do not go deep on app quality, but the broader Zepp ecosystem has historically been functional rather than outstanding compared to Garmin Connect. If you are coming from years of Garmin's training load tools and structured workout library, expect a step down in depth, not a lateral move.</p><p><strong>HYROX and gym accuracy</strong> is a useful data point for cross-training runners. In a HYROX simulation comparison, the Cheetah 2 Ultra matched the Whoop MG on accuracy. For runners who mix track sessions with gym work, this matters.</p><h2>Who it's for / who should skip it</h2><p><strong>Buy it if:</strong> You want a trail-capable watch with genuinely strong optical heart rate accuracy, 55 hours of GPS runtime, and you can live without Garmin's ecosystem depth. The Ultra makes sense for runners who push hard in varied conditions and have been burned by wrist HR sensors in the past. The data here suggests this one is different.</p><p><strong>Skip it if:</strong> You are a GPS-obsessed trail runner where every metre of route accuracy matters. The Forerunner 970 at the same price is the better call in that scenario. Also skip it if app ecosystem depth, sleep tracking detail, or training analytics are central to your workflow. The Zepp platform does not compete with Garmin Connect on analytical depth, and the sources reveal no information on sleep tracking quality to reassure you there.</p><p><strong>The £150 premium over the Cheetah 2 Pro</strong> is harder to justify on paper since the spec sheets look almost identical. The GPS improvement from 73% to 81% and better HR consistency are real, but whether that gap matters depends entirely on how serious your running is and how often you push the limits of the hardware.</p><h2>Verdict</h2><p>The Amazfit Cheetah 2 Ultra is a better watch than the price-to-brand ratio suggests, with optical HR accuracy that genuinely challenges reference devices across multiple test formats. GPS falls just short of the Forerunner 970, and the app ecosystem is the weak flank. At £599.90, it is a serious option if you are open to running outside the Garmin ecosystem.</p>