The choice between buying a dedicated running watch and just using a phone for tracking has become genuinely uncertain over the past five years. Phones have gotten better at GPS. Apple Watch and Galaxy Watch have closed most of the gap with dedicated running watches. The price-to-features ratio of entry-level GPS watches has improved. The result is that the case for a dedicated running watch is no longer automatic, and many recreational runners can get most of what they need from a phone or a general smartwatch.
The case for a dedicated running watch is also real and substantial for the right user. Long-distance runners, triathletes, trail runners, and runners who care about granular training data still benefit meaningfully from a purpose-built watch. The question is which category you fall into and how much the marginal differences are worth.
GPS accuracy: the real picture
Modern dedicated running watches with multi-band GPS (sometimes marketed as “dual-frequency” or “multi-frequency”) track distance within roughly 1 to 2 percent of true distance in typical conditions. The Garmin Forerunner 265, Coros Pace 3, Apple Watch Ultra 2, and Garmin Fenix 8 all sit in this range.
Single-band GPS watches (older models, entry-level GPS watches) typically track within 2 to 4 percent of true distance. The error increases in urban canyons, dense forests, and near tall structures that reflect GPS signals.
Modern smartphones, when carried in a hand or armband with the GPS app running actively, track within 3 to 6 percent of true distance. Phones in pockets, especially back pockets, can drift to 5 to 10 percent error due to signal blockage from the body.
In practical terms: a 10-mile run might measure 9.85 miles on a high-end running watch, 9.7 miles on a phone in armband, or 9.5 miles on a phone in a back pocket. For general fitness, all three are close enough. For competitive training where pace targets matter, the difference between 9.85 and 9.5 is meaningful.
The biggest accuracy differentiator is multi-band GPS, not the watch versus phone distinction. A phone with a modern chipset (iPhone 15 or newer, Pixel 8 or newer) running a dedicated GPS app like Strava or Garmin Connect is often as accurate as a mid-range running watch.
Heart rate accuracy
Wrist-based optical heart rate sensors have improved significantly. The Garmin Elevate Gen 5 sensor, the Apple Watch’s electrical sensor combination, and the Coros optical sensor all produce reasonably accurate heart rate data during steady-state runs.
Where wrist sensors still struggle:
Interval workouts with rapid heart rate transitions. The sensors lag by 10 to 30 seconds in catching rapid changes.
Cold weather and cold skin. Reduced blood flow to the wrist degrades signal quality.
High-intensity efforts where wrist movement causes signal noise. The lateral arm swing of fast running creates artifacts.
Wrist tattoos. Some tattoo inks block the optical signal entirely.
A chest strap heart rate monitor paired to a watch or phone improves accuracy in all these scenarios. Chest straps measure electrical impulses directly from the heart and are typically within 1 to 2 bpm of true heart rate even during intervals.
For most general fitness tracking, the wrist sensor is sufficient. For interval-focused training or research-grade data, a chest strap is the better tool.
Battery life comparison
This is the area where dedicated running watches still pull significantly ahead.
Garmin Forerunner 265: 13 days in smartwatch mode, 20 hours in standard GPS.
Coros Pace 3: 17 days in smartwatch mode, 38 hours in standard GPS.
Garmin Fenix 8: 16 days in smartwatch mode, 84 hours in standard GPS.
Apple Watch Series 10: 18 hours typical use, 5 to 8 hours in GPS workout mode.
Apple Watch Ultra 2: 36 hours typical use, 12 hours in GPS workout mode.
Galaxy Watch 6: 30 to 40 hours typical use, 6 to 8 hours in GPS workout mode.
iPhone 15 with GPS running app: roughly 30 percent battery drain per hour of running.
For runners doing 30 to 60 minute sessions a few times per week, smartwatch battery life is sufficient. For ultramarathoners, multi-day events, or anyone wanting to avoid daily charging, the dedicated running watch is the clear winner.
Training data and features
Dedicated running watches provide an integrated training ecosystem that smartphones and smartwatches do not fully match.
Garmin and Coros watches include:
VO2 max estimates from running pace and heart rate Training load tracking across weeks Recovery time estimates after workouts Race predictor times for various distances Performance condition assessments during runs Lactate threshold estimation Heat and altitude acclimation tracking Running power (Stryd compatibility or built-in) Multisport tracking (triathlon transitions, swimming, cycling)
Apple Watch and Galaxy Watch include some of these via Apple Fitness, Strava, or third-party apps, but the integration is less seamless and some metrics (training load, recovery time) are less developed.
Phone-only tracking via Strava or similar apps offers the basic data (pace, distance, heart rate via paired strap) but rarely the advanced training metrics.
For runners who actively use training data to structure their workouts, the running watch ecosystem is meaningfully more useful. For runners who just want to know how far they ran and at what pace, the phone is sufficient.
Convenience and practical considerations
Running with a phone has practical drawbacks. The weight and bulk of a phone in a pocket or armband is noticeable over long runs. The phone is at risk in rain, on trails, or in any fall. Battery depletion during long runs (especially with GPS, music, and screen activity) can leave you without a phone when you need it for safety.
Running with a watch is more or less invisible after the first few uses. The watch is rugged enough to handle weather, falls, and contact. Battery life is rarely a concern in normal weekly use.
For runners who want to leave the phone at home during runs, the watch is necessary. For runners who carry a phone anyway (for music, safety calls, photography), the phone GPS is “free” in the sense that no additional device is needed.
Cost comparison
Entry-level dedicated running watch (Garmin Forerunner 55, Coros Pace 2): 150 to 200 dollars.
Mid-tier running watch (Garmin Forerunner 265, Coros Pace 3): 300 to 450 dollars.
High-end running watch (Garmin Fenix 8, Garmin Epix Pro): 700 to 1000 dollars.
Apple Watch Series 10: 400 to 500 dollars.
Apple Watch Ultra 2: 800 dollars.
Phone GPS apps (Strava premium, Garmin Connect): 0 to 80 dollars per year.
For a runner who would not otherwise wear a smartwatch, a dedicated running watch in the 200 to 400 dollar range is a reasonable investment for serious training. For a runner who already owns or wants an Apple Watch or Galaxy Watch for general use, the dedicated running watch is often redundant.
Who needs a running watch
The clear use cases for a dedicated running watch:
Marathon and ultramarathon runners who need long battery life and advanced training metrics.
Trail runners who need rugged build and accurate GPS in challenging conditions.
Triathletes who need multisport tracking.
Serious training programs that depend on heart rate zones, training load, and recovery metrics.
Runners who do not want to carry a phone during runs.
Who can skip it:
Casual runners doing 3 to 5 sessions per week of 30 to 60 minutes.
Runners who already own a capable smartwatch and use it for fitness.
Runners just starting out who are not yet sure how committed they will be.
For more on watch selection and testing methodology, see our methodology.
Frequently asked questions
Is a running watch more accurate than my phone for GPS?+
For most modern dedicated running watches, yes, slightly. Watches with multi-band GPS (Garmin Forerunner 265, Coros Pace 3, Apple Watch Ultra) typically track distance within 1 to 2 percent of actual. Phone GPS is accurate within 2 to 4 percent depending on the phone, the app, and where you carry the phone during the run. The difference matters for serious training but not for general fitness tracking.
Do I need a running watch if I have an Apple Watch or Galaxy Watch?+
For most recreational runners, no. The Apple Watch Series 9 onward and Galaxy Watch 6 onward have GPS accuracy and heart rate tracking close to dedicated running watches. The main differences are battery life (running watches last days or weeks, smartwatches last 1 to 2 days), training-specific features, and ruggedness. If you already own a capable smartwatch, the upgrade to a running watch is not always necessary.
How accurate is phone GPS for running compared to a watch?+
Modern phone GPS is accurate within 5 to 15 meters in typical conditions, which translates to 2 to 4 percent error over a typical run. The error is higher in urban canyons, dense tree cover, and when the phone is in a pocket or back-mounted armband. Holding the phone in hand or wearing it on the upper arm produces the best phone-based accuracy.
What can a running watch measure that a phone cannot?+
Continuous heart rate (via the wrist sensor or paired chest strap), VO2 max estimates, training load and recovery time, race-pace alerts on demand, cadence directly from wrist accelerometer, and altitude via barometric sensor. Phones can match some of these with paired heart rate straps or specialized apps, but the watch integrates the data more seamlessly.
How long should a running watch battery last?+
In GPS mode (continuous tracking during runs), modern dedicated running watches last 10 to 40 hours depending on the model and GPS mode. The Garmin Forerunner 265 lasts about 20 hours in standard GPS mode and 6 days in smartwatch mode. The Apple Watch Ultra 2 lasts about 12 hours in GPS workout mode and 36 hours in normal use. A phone running GPS for an hour drains roughly 20 to 30 percent of battery.
Related product reviews
Garmin Forerunner 265 Review (2026)
COROS PACE 3 Review (2026)
Apple Watch Series 10 Review (2026)
Garmin Fenix 8 Solar Review (2026)
Apple Watch Ultra 2 Review (2026)
Alex Patel
Alex Patel writes for The Tested Hub.