Do I Need a Running Watch? What Your Phone Covers at Each Level

No, you don't need a running watch to start running. A phone can play the NHS Couch to 5K coach, record your route and pace in an app like Strava, and play music. In a 2021 track study, a phone app's distance error was only slightly larger than two GPS watches'. A watch starts to earn its place once your plan is written in miles rather than minutes, from about the 10K stage, and by marathon training it's the easier tool for most of what you'll track.

The short answer, by level

What your phone already does

It coaches. The NHS Couch to 5K app is the plan: it builds week by week, offers a choice of trainers, and works with your music player. The NHS kit advice is built around it: "You'll need your phone to hear your Couch to 5K coach, so if you don't have a pocket, a running armband can help."

It records. Strava's help center says "the simplest way to get an activity onto Strava is to record it directly in the iOS or Android app." The app tracks your route and stats as you run and uploads when you finish. No watch involved.

It keeps you reachable. The Road Runners Club of America's runner safety tips call your cell phone "the best safety tool you own" and suggest slipping ID into the phone case. That is a reason to carry it even after you own a watch.

What the phone doesn't do well is sit where you can see it. Checking pace means pulling it out of a pocket, belt or armband mid-stride. On a 30-minute Couch-to-5K session that hardly matters, because the coach tells you what to do. On a 10-mile long run you'll check the numbers more often. Our guide to carrying your phone while running covers belts, armbands and the options without an armband.

Watch vs phone: is a watch more accurate?

A little, in the one head-to-head study we found, and not by enough to change what you buy. A 2021 validation study in the journal Sensors had 36 adults run on a 400 m stadium track while wearing two watches (a Garmin Forerunner 945 and a Polar Ignite) and carrying a phone app (Polar Beat on an iPhone 7). On a 3 km run, the mean absolute percentage error in distance was 1.44% for the Garmin, 1.88% for the Polar watch and 2.67% for the phone app. On a 1.6 km interval run it was 1.65%, 2.66% and 3.35%.

So the watches were ahead, but everything stayed under 4% in that test. On a 5K run, a 3% error is less than a tenth of a mile, by our arithmetic. Watches aren't perfect either: a 2020 study of eight sport watches from Apple, Coros, Garmin, Polar and Suunto found mean absolute percentage errors from 3.2% to 6.1%, with distances generally underestimated in urban and forest areas.

When a watch starts to help

• When your plan is written in miles. Higdon's Novice 10K asks for runs of set distances. The watch tells you when you've covered them, which beats guessing or stopping to check a phone.
• When you want numbers at a glance. Higdon tells novices to run at a pace that lets you "converse comfortably." A watch shows your pace on your wrist, so you can check you haven't drifted faster without breaking stride.
• When you want a plan on your wrist. Garmin lists its running coach and daily suggested workouts on the Forerunner 70, so the watch tells you what today's run should be.
• When long runs get long. By the half, the long run reaches 10 miles; by the marathon, 20. Dedicated running watches list battery in days: Garmin rates the Forerunner 70 at up to 13 days as a smartwatch.
• When you'd like to leave the phone behind. Watches with music storage, like the Garmin Forerunner 170 Music, can play music without the phone. Weigh that against the RRCA's advice to carry it.

A good moment to buy is Couch-to-5K graduation, or the day you sign up for a 10K. Our best running watches for beginners ranks six watches for exactly that point.

Running with just your phone: how to make it work

Plenty of runners never buy a watch, and nothing in the Couch-to-5K or Novice 10K plans requires one. If you're staying phone-only for now, a few habits make it easier.

1. Carry it low and snug. A phone bouncing in a loose pocket is the most common complaint. In its running-belt guide, iRunFar says the most common cause of a bouncing belt is wearing it in the wrong place, and that tube belts work best lower on the hips, over the widest part of the pelvic bone.
2. Start the app before you start running. Open the NHS coach or Strava while you're still at the door, so the first interval or the first mile isn't spent fiddling with a screen.
3. Don't chase exact distance. Higdon tells novices not to worry about speed and to cover the distance, or approximately the distance, suggested each day. A phone reading 3.4 miles on a 3.5-mile day is fine.
4. Keep the volume down. The RRCA suggests keeping music low enough that you can stay aware of your surroundings, and texting a friend or family member so they know you're out.

When those habits start to feel like work, usually around the first long runs of a half-marathon plan, that is the sign a watch will make running simpler.

Is the Apple Watch good for running?

Yes, for many runners, with two catches. Apple's Series 12 spec page lists Training Load, custom workouts, Pacer, Race Route and running power, plus running form metrics including cadence, stride length, ground contact time and vertical oscillation. It uses Precision L1 GPS (GPS, GLONASS, Galileo, QZSS and BeiDou) and offers offline maps.

The first catch is battery. Apple rates the Series 12 for up to 24 hours of normal use (up to 38 in Low Power Mode) and up to 10 hours of outdoor workout, so most owners charge it daily. The second is compatibility: it requires an iPhone 11 or later on iOS 27 or later.

Running watch vs Apple Watch, then: if you already wear an Apple Watch and your runs are 5K to half marathon, it's a capable running watch and you don't need a second one. For an 18-week marathon build, a dedicated running watch that lasts days between charges is the easier partner. The best GPS watches for marathon training are ranked with that in mind.

If you buy one: what to look for

• Coaching you'll follow. A new runner gets the most from a watch that suggests the day's run. Garmin lists running coach on its Forerunner 70 and 170 Music.
• Days between charges. Check the smartwatch figure, not just GPS hours, and note what the maker says the always-on display costs. The Forerunner 70 is up to 13 days, or 5 with the display always on.
• Music, if you want to go phone-free. The Forerunner 70 has no music storage; the 170 Music does. Garmin lists up to 7.5 hours GPS-only while playing music on the 170.
• Your phone. The Apple Watch is iPhone-only. Check the maker's compatibility list before buying any watch.
• Features you'll use this year. Maps and multi-band GPS are marathon features. If you are weighing brands, our Garmin vs COROS comparison goes model by model.

Do you need a running watch for Strava?

No. Strava records runs directly in its iOS and Android apps, and says that for wearables like Garmin and Apple Watch, "most devices sync to Strava automatically once they're connected." So you can start on the phone and add a watch later without losing your history on Strava. COROS lists sync with Strava and TrainingPeaks for the Pace 4 as well.

If you're still at the start, sort the essentials first: shoes, something to carry the phone, and the plan. Our Couch-to-5K gear checklist lists what a first-time runner actually needs.