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Choose by phone and training style: the Apple Watch Series 12 is the broad smartwatch pick for iPhone users, the Garmin Forerunner 970 is aimed at dedicated runners, and the COROS Pace 4 Pro is a running-focused alternative with longer listed battery life and a lower U.S. launch price than Garmin’s. None is a proven universal winner for wrist heart-rate accuracy; results depend on the workout and wearer.
Which fitness smartwatch fits your training?
| Watch | Best fit | Evidence to weigh |
|---|---|---|
| Apple Watch Series 12 | iPhone users who want a general-purpose smartwatch alongside workout tracking | A Tom’s Guide review published October 3, 2026, reported mostly accurate readings during the reviewer’s runs, with brief periods at run starts when the watch withheld a reading. The test included more than 100 running miles and several other workouts, but it was one tester’s experience. |
| Garmin Forerunner 970 | Runners prioritizing dedicated training and running data | In one March 2026 half-marathon comparison, its heart-rate readings stayed closer overall to a chest strap than the Apple Watch Ultra 3’s readings. That is a single-run comparison, not a general accuracy ranking. |
| COROS Pace 4 Pro | Runners seeking a running-focused watch with longer listed battery life and a lower launch price than the Forerunner 970 | A September 2026 review reported generally close chest-strap comparisons during running and cycling, with more heart-rate errors during strength workouts. The hands-on test was short. |
These are use-case recommendations, not a controlled head-to-head ranking across all three watches. The available testing differs by model, activity, tester and comparison method.
How accurate is smartwatch heart rate during exercise?
Wrist watches use optical sensors that infer pulse from light, while a chest strap reads electrical signals from the heart. Movement and workout type can affect wrist readings, so a watch may track one activity well and struggle during another. Fit and individual conditions also matter.
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In a 2017 peer-reviewed study, agreement for the older optical monitors tested varied by aerobic exercise, with the strongest agreement on a treadmill and the weakest on an elliptical. Those devices are from earlier generations; the study supports caution about activity-dependent readings, not a ranking of current watches. A 2026 study summary also indicates differences by exercise type, but detailed results and methods are not available to support a product comparison.
#1 Best Overall
- 👍【Your Ultimate Fitness Partner】With 120+ sport modes, this smart watch for android phones covers running, cycling, hiking, yoga, skiing, and more. It accurately tracks heart rate, steps, calories, distance, and activity time. Acting as your wrist-based coach, it helps optimize training intensity. IP68 waterproof design lets you train through sweat and rain. Unleash your fitness potential anywhere.
- 📞【Bluetooth Calling & Smart Alerts】Stay connected hands-free. Our smart watche for women features advanced Bluetooth 5.3 for stable calls directly from your wrist. The built-in HD speaker and mic deliver crystal-clear audio, while smart vibration alerts notify you of messages from apps like Facebook and WhatsApp. Perfect for driving, workouts, or busy days—never miss a call or important update again.
- ⌚【1.83" HD Touchscreen & 200+ Faces】Experience the vibrant full-color display, perfect for checking info on-the-go. Choose from 200+ faces or use your photo to match any style, from workouts to daily life. More than a watch—it's the android smartwatch that matches your life.
- 🚀 【Your 24/7 Wellness Companion for Smarter Choices】From busy workdays to restful nights, this smart watche for men is with you. It tracks your heart rate and stress during meetings, analyzes your deep and light sleep, and provides a morning readiness report. It also features female health tracking. All your data is clearly displayed, helping you make smarter daily choices for a healthier, more balanced life.
- 💖 【7-Day Battery & Universal Compatibility】Say goodbye to daily charging. This smart watch lasts up to 7 days on a single 2-hour charge and stays ready for 30 days in standby mode. It seamlessly pairs with both iOS and Android devices, including Apple iPhone, Samsung, and Google Pixel. Enjoy total freedom from battery anxiety and stay connected effortlessly.
What the hands-on comparisons actually found
Apple Watch Series 12: a multi-workout test
In a Tom’s Guide review published October 3, 2026, the reviewer compared Series 12 readings with a Garmin HRM 600 chest strap across more than 100 running miles, two strength workouts, a bodyweight HIIT session and an indoor bike ride. The reviewer described the vast majority of run data as very accurate, while noting short periods at the beginning of runs when the watch did not provide a reading. This evidence is specific to that tester and those sessions; it does not establish results for every wearer or workout. Read the Series 12 heart-rate test.
Forerunner 970 and Apple Watch Ultra 3: one half-marathon
In a March 25, 2026 Tom’s Guide comparison, one runner wore both watches on a 13.1-mile course and used a Garmin HRM 600 as the heart-rate reference. The Forerunner 970 recorded 13.15 miles and the Ultra 3 recorded 13.22 miles; the reviewer considered both GPS tracks close and the Garmin distance nearer the official course distance. On that run, average heart rate was 158 beats per minute for the strap, 156 for Garmin and 172 for Apple; maximum readings were 174, 172 and 203, respectively.
Rank #2
- Designed with a bright, colorful AMOLED display, get a more complete picture of your health, thanks to battery life of up to 11 days in smartwatch mode
- Body Battery energy monitoring helps you understand when you’re charged up or need to rest, with even more personalized insights based on sleep, naps, stress levels, workouts and more (data presented is intended to be a close estimation of metrics tracked)
- Get a sleep score and personalized sleep coaching for how much sleep you need — and get tips on how to improve plus key metrics such as HRV status to better understand your health (data presented is intended to be a close estimation of metrics tracked)
- Find new ways to keep your body moving with more than 30 built-in indoor and GPS sports apps, including walking, running, cycling, HIIT, swimming, golf and more
- Wheelchair mode tracks pushes — rather than steps — and includes push and handcycle activities with preloaded workouts for strength, cardio, HIIT, Pilates and yoga, challenges specific to wheelchair users and more (data presented is intended to be a close estimation of metrics tracked)
The reviewer reported that the Ultra 3 often read too high or could not obtain a reading, while the Forerunner 970 stayed close to the strap overall but had some start-up delay and erroneous dips. These figures describe one runner on one course and should not be treated as expected results for other users or as a test of the Series 12. Read the half-marathon comparison.
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Tom’s Guide’s September 2026 review found Pace 4 Pro chest-strap comparisons generally close during runs and rides, with more errors in strength workouts. The review described short hands-on testing, so the results are useful as an example of how readings can vary by activity, not as a population-level accuracy result. Read the COROS Pace 4 Pro review.
Rank #3
- 📞 【Bluetooth 5.3 Calls & Smart Notifications】 Make and answer calls directly from your smartwatch with stable Bluetooth 5.3 connectivity. Receive vibration alerts for calls and messages from Facebook, WhatsApp, Instagram, Twitter and more.
- ⌚ 【1.96 HD Touch Screen & 200+ Watch Faces】 Enjoy a large 1.96 HD full-touch display with smooth operation and clear visuals. Choose from 200+ watch faces in the GloryFit app or customize the screen with your favorite photo.
- 💖 【24/7 Health Monitoring】 Track heart rate, blood oxygen, stress, sleep and daily activity with built-in sensors. View your health and activity data in the GloryFit app to better understand your daily wellness.
- 🏊 【110+ Sports Modes & IP68 Waterproof】 Supports 110+ sports modes including running, walking, hiking, cycling, basketball and fitness. Tracks steps, calories, distance and heart rate during workouts. IP68 waterproof for daily exercise, sweat and hand washing.
- 🚀 【7-Day Battery & Multiple Smart Features】 Enjoy up to 7 days of use and about 30 days of standby after a 2-hour charge. Includes alarm, timer, stopwatch, music control, weather, camera control, calculator, sedentary reminder and more. Compatible with Android and iPhone.
Battery life and launch pricing for the COROS Pace 4 Pro
Tom’s Guide reported a U.S. launch price of $449 and a U.K. launch price of £389 for the Pace 4 Pro on September 22, 2026. Its listed specifications were up to 21 days in watch mode and 30 hours of multi-band GPS use in the most accurate mode. These are launch/listed figures, not current verified offers or independent battery-test results. Check current local price and availability before buying.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.When should you use a chest strap?
A chest strap is worth considering if responsive workout heart-rate data is important to your training, or if you want a reference to compare against your watch. Recent Tom’s Guide comparisons used a Garmin HRM 600, but compatibility varies; verify that a specific strap works with your watch before purchase. A strap is a comparison and training tool, not proof that every wrist reading is wrong.
Quick Recap
Best Value
- Easy-to-use running smartwatch with built-in GPS for pace/distance and wrist-based heart rate; brilliant AMOLED touchscreen display with traditional button controls; lightweight design in 43 mm size
- Up to 11 days of battery life in smartwatch mode and up to 19 hours in GPS mode
- Reach your goals with personalized daily suggested workouts that adapt based on performance and recovery; use Garmin Coach and race adaptive training plans to get workout suggestions for specific events
- 25+ built-in activity profiles include running, cycling, HIIT, strength and more
- As soon as you wake up, get your morning report with an overview of your sleep, recovery and training outlook alongside weather and HRV status (data presented is intended to be a close estimation of metrics tracked)
Rank #4
- 【Crystal-Clear Communication】AEAC smartwatch delivers clear call quality with high-definition speakers and microphones. Built with an AI assistant, it enables smooth voice commands and hands-free calls.
- 【Comprehensive Health Monitoring】The AEAC smartwatch tracks vital health metrics—blood oxygen, heart rate, stress, and sleep analysis—providing you with valuable insights for enhanced well-being.
- 【Long-Lasting Battery】Enjoy up to 10 days of use on a quick 2-hour charge. Will monitor your heart rate, steps, activity routes, and calorie burn around the clock, offering a complete view of your health and fitness.
- 【110+ Sports Modes & Waterproof】With 110+ sports modes, this fitness watch supports a wide range of activities, from yoga to swimming. Its 3ATM water-resistant design ensures reliable performance in wet conditions.
- 【1.32" AMOLED Touchscreen】 Features a 1.32-inch AMOLED display for sharp visuals and smooth responsiveness. The watch face measures 43 mm, offering a clear and comfortable viewing area. Choose from 200+ watch faces or personalize with your own photos, making the watch uniquely yours
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
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