For the New York City Marathon, I wore seven wearables on my wrist and trained with them for 18 weeks to determine which trackers can help you cross the finish line.
Over 508 miles of running, 30 strength workouts, and 110-mile rides, as well as weekly mobility exercises, I judged comfort, live metrics, recovery insights, battery life, and overall value. The course and the lead-up served as a punishing real-world lab, and a few devices quickly separated themselves.
How I tested seven marathon-ready fitness trackers in NYC
Each week of training, I profiled one device, but on all seven trainers I did a quality session to compare the GPS tracks, heart rate curves, and elevation readings side by side. I wore them day and night to test sleep and recovery features, and monitored battery decline on long runs as well as multi-hour travel days. My short list was:
- Apple Watch Ultra 3
- Garmin Forerunner 570
- Suunto Run
- Pixel Watch 4
- Fitbit Charge 6 (Fitbits are turtle slow)
- Oura Ring 4
- Whoop MG
Why the NYC Marathon course exposes wearable weaknesses
The NYC Marathon is a torture test for sensors and endurance. You can be out of the house for five hours before your wave goes off, then fly through five boroughs that include bridges and wind and humidity-creating concrete urban canyons that make GPS wonky. At large New York Road Runners races, the organization routinely has more than 50,000 finishers who can cram the starts and surge yahooingly past their friends and wannabe pacers on demand, which outstrips wrist-based heart rate. Independent test analyses by the likes of DC Rainmaker, along with platform data from Strava, have long displayed urban GPS drift on the order of 1–5% and/or spikes on bridges — which is precisely what I saw on my files.
The serious runner’s standouts from months of testing
Garmin Forerunner 570 provided the greatest depth of training information. Live pages were bright, even in full sun, and post-run metrics — training effect, running dynamics, power, and adaptive plans — were a cut above the rest. The trade-off was comfort; the stock band gave me such bad chafing after a soggy run. Swap the strap, and it’s the best full-service runner’s tool I tested, thanks to multi-day battery life that laughed at the marathon.
Apple Watch Ultra 3 — I didn’t leave home without it on race day. A generously sized screen meant I could quickly glance at pace and heart rate simultaneously, the action button simplified splitting manual laps, and the battery lasted through an extended pre-start as well as 26.2 miles of running. The health tracking is wide, not deep, but for runners who want good smartwatch features with dependable marathon battery life, this was great.
Suunto Run impressed with a smart mix of simplicity and substance. The light Velcro strap stayed secure and comfortable through sweaty tempo work and overnight sleep. In-run pages were essentials-focused, while Suunto’s app unpacked load, stress, and normalized graded pace clearly. Diminutive smartwatch perks and a cheap-feeling charger prevent it from reaching all of its potential, but the value is high for data-minded runners who don’t require app stores or payments.
Whoop MG was the best recovery guide. There’s no screen and the strap is soft; it vanishes from your wrist, while its strain, sleep staging, and HRV trends made it easy to decide when to push or back off, as the journal correlations — alcohol, late meals, even travel — proved reliably helpful. It doesn’t have live pace or GPS, so you’ll want a second device for training. But for readiness monitoring, it was the best. The rub is the cost of a subscription.
Good ideas that fell short in marathon-level use
The Oura Ring 4 was the most unobtrusive wearable I tested, and a very good sleep tracker with temperature trends that helped me tap into recovery and cycle insights. As a marathon tool, however, it’s strictly supplementary; there is no in-run feedback and nearly zero immediate workout analysis. Just wear it with a real watch if you care about splits and cadence.
Pixel Watch 4 learned well but flubbed the marathon’s endurance test. It endured long workouts in training, provided bright visuals, and surfaced useful running form metrics within Fitbit’s platform. On race day — after hours in the cold start area and 26.2 miles — it died. If the marathon logistics are anything like NYC’s long waits, budget for external battery strategies or select a device with a more generous energy reserve.
Fitbit Charge 6 was an affordable tracker with exceptional heart rate alerts and fantastic battery life that rarely fell short of a week. It was also difficult to get consistency from GPS distance — within a tenth of a km each time — and no elevation tracking on a hilly course is pretty weak. I used it fine for everyday activity, but in marathon training it acted more like an upscale step counter than a racing tool.
What I’d wear for 26.2 and through a full training block
For a training block: Whoop MG for recovery and Suunto Run for workouts. If you don’t mind spending more than double and want all the metrics, choose Garmin Forerunner 570; you can pop in a softer band in place of the strap that comes with it. For racing on the day itself, Apple Watch Ultra 3 was readable, reliable, and communicated on the move. This combo tackled preparedness, training, and the special needs of race day without letting me down when I needed it most.
Big picture, the ideal marathon setup is one that balances live data with recovery intelligence. The ACSM notes that HRV and sleep can inform load management, and my experience supported that: The right recovery cues pared those junk miles away while sharpening the quality days. Choose the device that fits on your wrist and in your logistics, then let consistent training — not numbers — do the heavy lifting.