Race-day wearable checklist: set up your watch, pace from it, and know why it reads long.

By Raji Shah · Updated 2026-10-24

Race day is not the time to test new settings. Set your watch up during race week, try the setup on a run at goal pace, and you will have one less thing to think about on the start line. This checklist covers what to do and when, how to pace from your watch, and the one thing every runner should know before the gun: your watch will probably say the race was longer than it was.

Race week

• Hold off on firmware updates in race week unless one fixes a problem you already have. If you must update, do it early in the week and test the watch on a run, so a failed update or a changed setting doesn't surprise you on race morning. Our guide to COROS update problems covers what to do if one fails.
• Build one race data screen and keep it simple: lap pace or average pace, elapsed time, distance, and heart rate if you use it. Turn off auto-pause, so crowded starts and aid stations don't pause your timer, and use the screen on a run at goal pace so you know where each number sits.
• Decide how you will lap. Auto Lap at every mile or kilometer is easiest, but because your watch reads long, its laps drift ahead of the course markers. Pressing lap at each official marker keeps your laps lined up with the course, so each lap time is your real split for that mile or kilometer. On the Forerunner 970, 570 and fenix 8, Garmin's Auto Select option instead triggers laps at the course's own mile or kilometer points when you follow a loaded course with timing gates, such as some certified marathons. If you press the lap key by mistake, Garmin usually gives you a few seconds to discard that lap. Don't combine manual laps with a structured workout: on Garmin and COROS watches, the lap button moves a workout on to its next step.
• Load a pacing plan or course if your watch supports one. Garmin's PacePro builds a pace band for a course and adjusts the target paces for hills; you need to create the course in Garmin Connect first. COROS's Pace Strategy works from a preset distance, or from a saved route with target paces adjusted for elevation. Apple Watch's Pacer and Polar's Race Pace show whether you're ahead of or behind one target. Apple's Race Route only works on a route you've already run at least twice, so it won't cover a new race course.
• Choose a satellite mode and check the battery estimate for your race time. Multi-band GPS can help among tall buildings and trees, but it costs battery: Garmin rates the Forerunner 970 at up to 26 hours with GPS only and 21 hours with All + Multi-Band, and the Forerunner 570 (47 mm) at 18 and 14 hours. COROS recommends All Systems for everyday runs and says dual-frequency mode uses much more battery. Among Apple watches, only the Ultra models have dual-frequency GPS; Apple rates the Series 12 at up to 10 hours of workout tracking and the Ultra 4 at up to 18, or 25 in Extended Workout mode. Leave a margin beyond your expected finish time.
• Pair and test your chest strap, if you use one, and replace its battery if it is old.
• Silence notifications for the race, so a message doesn't cover your pace mid-race.

The night before

• Charge the watch, any heart-rate strap, and your earbuds; if they drop out on runs, see our guide to AirPods disconnecting with a Garmin.
• Sync the watch so the pacing plan, course or workout is actually on it.
• Check the watch isn't set to a battery-saving mode that records GPS less often, unless you chose that on purpose for a long race.
• Write your goal splits somewhere you can see them, such as a pace band, in case the watch fails.

Race morning and the start line

• Get a satellite fix before the corral. Garmin says finding satellites can take 30 to 60 seconds and suggests standing still for a few minutes; the GPS status bar turns green when the watch is ready. Syncing the watch the day before downloads several days of satellite data, which helps. Do it in the open, before you're packed into a crowded start among tall buildings. On a Garmin, the run screen times out to low-power watch mode after 5 minutes with Power Save Timeout set to Normal, or 25 minutes on Extended, so choose Extended or reopen the run a few minutes before the start.
• Wet your chest strap's sensors before you put it on, as Garmin's strap manuals advise, and reapply water if readings look erratic early on.
• Start the watch as you cross the start mat, not at the gun, so your time matches your chip time.
• Don't chase the watch in the first mile. Pace readings jump around among tall buildings, and weaving through the crowd adds distance, so check your elapsed time at the first marker against your goal split, and ease off if you're ahead of it.

Why your watch usually says the race was long

Certified road courses are measured along the shortest possible route a runner could take within the road the race uses. World Athletics' rules say "the length of the course shall not be less than the official distance". Course measurers ride a calibrated bicycle along that line, cutting every corner about 30 cm from the curb, and add a safety margin of one meter per kilometer so the course won't come up short if it's remeasured. A certified marathon is therefore laid out at about 42.24 km, 42 m more than 42.195 km.

Almost nobody runs that line. You weave around other runners, swing wide at corners and cross the road to aid stations, and every meter adds to what you actually run. USA Track & Field's own position on GPS says that because most runners don't run the shortest route, the distance on their GPS device "will usually be longer than the certified length of the course", even when the course was measured correctly.

GPS adds its own error, in both directions. In a study at a German marathon on a mostly open course, finishers' sport watches averaged 42.33 km for the marathon and 21.18 km for the half, both about 0.3 to 0.4% long, while readings from all devices, phones included, ranged from 41.5 to 43.7 km for the marathon. In a validation study of eight watches, readings tended to be short among tall buildings and in forest, by up to about 9%, and long on an open track.

So don't use your watch's distance to judge the course, or your pace against the mile markers late in the race. Two habits help:

• Run the tangents. Where it's safe and allowed, take the shortest line through corners and bends, which is the line the course was measured on.
• Pace from the course, not the watch. Compare your elapsed time with goal splits at the official mile or kilometer markers, or press lap at each marker so each lap time is your real split.

How to pace a race from your watch

Use lap pace or average pace, not instant pace. Instant pace is calculated from a few seconds of GPS data, so it jumps around, especially among tall buildings or under trees. Lap pace smooths that out over a kilometer or mile.

The bigger pacing risk is starting too fast. In an analysis of 1.7 million recreational marathon finishes, a third of runners ran their first 5 km as their fastest segment of the race. In a study of 91,929 finishes in 14 US marathons, the second half took 14% longer than the first on average, 15.6% for men and 11.7% for women. Faster runners paced far more evenly: men who finished under 3 hours slowed by 5.6% on average, against 22.7% for men who took 5 hours or more. In an analysis of almost 2 million race records, 28% of men and 17% of women "hit the wall", slowing by at least 25% for 5 km or more after the 20 km mark, and the slowdown typically began around 29 km.

How you start matters. In the same analysis of 1.7 million finishes, the best average finish times came from runners whose first 5 km was close to their average race pace; a first 5 km 10% faster than that was associated with finishing about 37 minutes slower. Marathon world records have also moved toward more even pacing. A practical plan: run the first 5 km at or slightly slower than goal pace, hold an even effort through halfway, and only push in the last 10 km if you still feel strong. On hilly courses, pace by effort on the climbs instead; our hilly race pacing guide explains how.

Don't pace a race by your training heart-rate zones. Heart rate runs higher on race day, by about 20 bpm at the same speed in a 10K by one estimate, and it drifts upward over long races. Our heart-rate zones guide covers when heart rate is and isn't a good guide.

Race features by brand

These are the race-day tools each brand documents for its current watches. Menu names change between models and updates, so check your own watch's manual.

After the finish

Stop the watch as you cross the finish mat, so its time matches your chip time, then save the activity once you're through the finish area and let it sync. Your watch's distance won't match the race distance, and that's normal; your chip time is your official result. If you're recovering from a marathon, our post-marathon recovery guide explains why running can feel hard for a while afterward.

Bottom line

A race-day watch setup should be boring, tested and easy to read under stress. Set it up in race week, pace from lap or average pace rather than instant pace, start near goal pace instead of faster, and expect the watch to read a little long.

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