How to Use a GPS Watch for Interval Training

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You’ve read that intervals are the fastest way to get quicker. You’ve even got a GPS watch on your wrist that cost you £150+. But every time you try to set up an interval workout, you end up three menus deep in settings you don’t understand, and by the time you’ve figured it out, you’ve lost the motivation to actually run. Sound about right?

In This Article

Why GPS Watches Transform Interval Training

Running intervals by feel is how most people start. Sprint to the lamppost, jog to the next one, repeat until you feel sick. It works in a rough way, but it’s wildly inconsistent — your “hard” effort varies massively depending on how tired you are, how warm it is, and whether you had lunch 30 minutes ago.

From Guesswork to Precision

A GPS watch removes the guesswork. Instead of “sprint for a bit,” you’re running 400 metres at 4:30/km pace with a 90-second recovery jog. The watch beeps when you hit your distance, beeps again when recovery ends, and tracks exactly how consistent your splits were. After a few weeks of this, you can see whether you’re getting faster, holding pace better, or falling apart on the last rep.

The Data Advantage

I started intervals without a watch years ago — just using a stopwatch app on my phone. Then I switched to a GPS watch with structured workouts, and within a month I could see patterns I’d never noticed. My fourth rep was always my slowest, my heart rate recovery between reps was improving week on week, and my pace was far more consistent when the watch beeped at me versus going on feel. The numbers don’t lie, and they don’t flatter you either.

For a deeper dive into what all those metrics mean — VO2 max, training load, training effect — check out our GPS watch features guide. It’s worth understanding the data your watch collects before you start generating lots of it.

Interval Training Basics Before You Touch the Watch

Before diving into watch setup, let’s make sure the fundamentals are solid. A GPS watch is a tool — it makes intervals more effective, but only if the underlying workout makes sense.

What Counts as an Interval Workout

An interval workout alternates between high-effort periods (reps) and low-effort recovery periods. The effort can be measured by pace, heart rate, or perceived effort. The structure is defined by four variables:

  • Rep distance or duration — how long each hard effort lasts (e.g., 400m, 800m, or 3 minutes)
  • Rep intensity — how hard you run during the effort (e.g., 4:15/km or 85% max heart rate)
  • Recovery duration — how long you jog or rest between reps (e.g., 60 seconds, 90 seconds, or distance-based)
  • Number of reps — how many hard efforts in total (e.g., 6 × 400m)

Who Should Do Intervals

If you’re completely new to running, build a base of easy running first — at least 8-12 weeks of consistent running, 3-4 times per week, before adding intervals. Our Couch to 5K guide is a good starting point. Once you’re comfortably running 5K three times a week, your body can handle the stress of interval work.

For runners already doing regular easy runs, intervals 1-2 times per week will improve your speed, running economy, and cardiovascular fitness faster than adding more easy miles alone. The NHS recommends mixing vigorous activity like interval running into your routine, and research consistently shows high-intensity interval training produces greater improvements in VO2 max compared to moderate continuous training.

Runner checking a GPS smartwatch during outdoor training

Setting Up Your First Interval Workout

The approach varies by brand, but the principle is the same across Garmin, COROS, Polar, Apple, and others. You define the work period, the rest period, and the number of repetitions — then the watch guides you through it.

On-Watch vs App Setup

Most GPS watches let you create interval workouts in two ways:

  • On the watch itself — quicker for simple workouts, but fiddly on a small screen
  • Via the companion app — Garmin Connect, COROS app, or Polar Flow. Easier for complex workouts with multiple sets, warm-ups, and cool-downs

For your first time, use the companion app. You can see what you’re doing on a proper screen, save the workout, and sync it to the watch. After you’ve done it a few times, you’ll be fast enough to set up simple sessions on the watch directly.

A Good Starter Workout

If you’ve never done structured intervals before, start here:

  1. Warm up with 10 minutes of easy jogging.
  2. Run 6 × 400 metres at a pace about 30-45 seconds per km faster than your easy pace.
  3. Jog slowly for 90 seconds between each rep.
  4. Cool down with 5 minutes of easy jogging.

This is enough to stimulate improvement without destroying you. If the last two reps feel comfortable, increase pace slightly next time. If you can barely finish, slow down.

Garmin Interval Setup Step-by-Step

Garmin is the most popular GPS watch brand in the UK, so let’s start here. This works on the Forerunner 265, 965, 55, and most Venu models.

Using Garmin Connect App

  1. Open the Garmin Connect app on your phone.
  2. Tap “More” (bottom right) → “Training & Planning” → “Workouts.”
  3. Tap “Create a Workout” → select “Running.”
  4. You’ll see a default structure with a warm-up step. Tap it to edit — set it to “Open” (no target, just run easy until you press lap).
  5. Tap “Add Step” → select “Interval.”
  6. Set the duration (400m) and target (pace range, e.g., 4:15-4:30/km).
  7. Tap “Add Step” → select “Rest” → set to time (90 seconds) with no pace target.
  8. Tap “Repeat” to wrap the interval + rest into a set → set repeats to 6.
  9. Add a cool-down step (open, no target).
  10. Save the workout with a descriptive name (e.g., “6x400m @ 4:20”).
  11. Sync to your watch — it should appear under the Run activity’s workout list.

Running the Workout

On the watch, start a Run activity, then select “My Workouts” from the menu. Choose your saved workout. The watch will guide you through each phase — beeping at the start and end of each rep, showing your target pace on screen, and alerting you if you’re going too fast or too slow.

The real-time pace alert is what makes this useful. A gentle buzz when you drift above your target pace is much more practical than trying to check the screen while running hard. After three sessions, I found I could feel the right pace without looking at the watch at all — the structured practice calibrated my effort sense.

COROS Interval Setup Step-by-Step

COROS watches (PACE 3, APEX 2, Vertix) handle intervals slightly differently — they’re actually a bit simpler to set up.

Using the COROS App

  1. Open the COROS app → tap “Training” at the bottom.
  2. Tap “Create Workout” → “Running.”
  3. Add a warm-up block (open-ended or set duration).
  4. Tap “Add” → “Interval.”
  5. Set work phase: type (distance), value (400m), alert (pace zone or HR zone).
  6. Set rest phase: type (time), value (90 seconds).
  7. Set the number of repeats (6).
  8. Add a cool-down block.
  9. Save and sync to your watch.

COROS has a nice feature called “Training Calendar” where you can schedule workouts for specific days. The workout syncs automatically and appears as a notification when you start your run that day. Small thing, but it means one less step on training day.

On-Watch Setup for Simple Sessions

If you’re at the track and want to set up quickly:

  1. Start a Run activity.
  2. Long-press the back button to access workout settings.
  3. Select “Interval” → set work distance, rest time, and number of reps.
  4. Press start — the watch handles the rest.

This on-watch method is limited to simple interval/rest structures, but for straightforward sessions like 6 × 400m or 8 × 200m, it’s faster than opening the app.

Polar Interval Setup Step-by-Step

Polar watches (Vantage V3, Pacer Pro, Ignite 3) use Polar Flow for workout creation.

Using Polar Flow

  1. Open Polar Flow (web or app) → go to “Training” → “Create Workout.”
  2. Select “Running.”
  3. Add a warm-up phase — choose “Free” for open-ended.
  4. Add an interval phase → set duration (distance: 400m).
  5. Set a target: pace guide (e.g., 4:15-4:30/km) or heart rate zone.
  6. Add a recovery phase → set duration (time: 1:30).
  7. Set repeat count to 6.
  8. Add a cool-down phase.
  9. Save as a favourite and sync to your watch.

Polar’s strength is heart rate zone guidance during intervals. The watch vibrates when you enter and leave your target zone, which is particularly useful for heart rate-based interval training where you’re targeting specific zones rather than pace numbers.

Choosing the Right Interval Structure

Not all intervals are created equal. The length and intensity of your reps determines what fitness quality you’re developing.

Short Intervals (200-400m)

  • Pace: Fast — close to your fastest sustainable effort for the distance
  • Recovery: Equal to or longer than the work period (e.g., 200m fast, 200m jog)
  • What they develop: Speed, running economy, neuromuscular coordination
  • Good for: 5K and 10K runners wanting to improve their top-end speed
  • Example: 10 × 200m at 3:45/km pace with 200m jog recovery

Medium Intervals (600-1200m)

  • Pace: Roughly your 5K race pace
  • Recovery: 50-75% of the work duration (e.g., 4 minutes hard, 2-3 minutes jog)
  • What they develop: VO2 max, aerobic power, lactate tolerance
  • Good for: Runners wanting to improve 5K and 10K times
  • Example: 5 × 1000m at 4:30/km with 2:30 jog recovery

Long Intervals (1600m+)

  • Pace: Between 10K and half marathon race pace
  • Recovery: Short — 60-90 seconds standing or very slow jog
  • What they develop: Lactate threshold, endurance at speed
  • Good for: Half marathon and marathon training
  • Example: 4 × 1600m at 4:45/km with 90 seconds jog recovery

Pyramid and Ladder Sessions

These vary the rep distance within a single workout — for example, 200m, 400m, 600m, 800m, 600m, 400m, 200m. They’re excellent for staying mentally engaged (every rep is different) and training multiple energy systems. On your watch, you’ll need to build these as individual steps rather than using the simple repeat function.

Using Heart Rate Zones for Intervals

Pace-based intervals work well on flat terrain in consistent conditions. But on hills, in heat, or when you’re tired from yesterday’s run, the same pace requires very different effort levels. Heart rate zones solve this.

Setting Your Zones Correctly

Before using HR-based intervals, make sure your zones are accurate. The default zones most watches ship with are based on the crude “220 minus age” formula, which can be out by 10-15 bpm. Better options:

  • Run a max heart rate test — warm up thoroughly, then run 3 × 3 minutes at increasing effort with 2-minute rests, pushing as hard as possible on the last rep. Your peak reading is close to your max HR.
  • Use a recent race result — your average heart rate during a flat-out 5K is approximately 95-97% of your max.
  • Lactate threshold test — the most accurate but requires a sports science lab or a structured field test

Which Zone for Intervals

  • Zone 4 (85-90% max HR) — “threshold” intervals. These develop your ability to sustain fast paces. Reps of 4-8 minutes work well here.
  • Zone 5 (90-100% max HR) — “VO2 max” intervals. Shorter, harder efforts that max out your cardiovascular system. Reps of 2-4 minutes.
  • Recovery should drop to Zone 1-2 (60-75% max HR) between reps. If your HR isn’t dropping below 75% max during recovery, you need longer rest or you’ve done too many reps.

HR Lag — The Gotcha

Heart rate doesn’t respond instantly. At the start of a 400m rep, your HR might still be at recovery levels for the first 20-30 seconds. By the end of the rep, it’s peaking. This lag means HR-based alerts can be misleading for short intervals (under 2 minutes). For short reps, pace-based targets work better. Save HR-based guidance for intervals of 3 minutes or longer, where your heart rate has time to settle into the target zone.

Pace Alerts vs Heart Rate Alerts

Most GPS watches offer both types of alerts during interval workouts. Understanding when to use each one will make your training more effective.

When to Use Pace Alerts

  • Flat, consistent terrain — track, canal towpaths, flat park loops
  • Short intervals (under 3 minutes) — HR lag makes heart rate unreliable for short reps
  • Race-specific training — when you want to practice running at your goal race pace
  • Good conditions — mild temperatures, no wind

When to Use Heart Rate Alerts

  • Hilly terrain — the same pace uphill and downhill represents very different efforts
  • Hot or cold conditions — heat increases HR at any given pace; cold can suppress it
  • Fatigue management — after a hard week, your HR shows you the true cost of the effort
  • Long intervals (3+ minutes) — HR has time to reach a meaningful steady state
  • Recovery monitoring — watching HR drop between reps tells you about fitness

Using Both Together

Some watches let you set pace as the primary target with a heart rate ceiling as a safety limit. This is my favourite approach for tempo intervals — I target 4:30/km pace, but if my HR goes above 92% max, the watch warns me I’m overcooking it. It catches those days where you feel fine but your body is actually working harder than usual.

Reading Your Interval Data After the Run

The run is done, you’re bent over gasping, and your watch is showing you a summary screen. Here’s what to look for.

Key Metrics Per Rep

  • Average pace — was it consistent across reps, or did you slow down?
  • Max heart rate — did each rep push you to the same effort level?
  • Recovery heart rate — how low did your HR drop between reps? Lower is fitter.
  • Cadence — did your form hold up in later reps or did your stride shorten?

What Good Progress Looks Like

Over 4-8 weeks of consistent interval training, you should see:

  • Same pace at lower heart rate — the clearest fitness signal
  • More consistent splits — your first and last rep should be within 5-10 seconds per km
  • Faster heart rate recovery — HR drops more between reps as you get fitter
  • Ability to add reps or increase pace — progressive overload in action

Open your companion app after the run and look at the lap-by-lap breakdown. Garmin Connect, COROS, and Polar Flow all show individual rep stats. Export to Strava if that’s where your club mates are — Strava’s lap analysis is decent, and the social element keeps you accountable.

Running track with lane markers for interval training

Common Interval Mistakes Your Watch Can Fix

Going Too Hard Too Early

The classic mistake: smashing the first two reps because you feel fresh, then dying by rep four. Your watch fixes this by beeping when you’re above target pace. Listen to it. The first rep should feel controlled, even easy. If the last rep is the hardest but you still hit the pace, you got the session right.

Inconsistent Recovery

Without a watch, recovery between reps gets looser as you tire. “90 seconds” becomes “when I feel ready,” which becomes 3 minutes by the sixth rep. Your watch holds you to the programmed recovery time. It’s unforgiving, but that’s the point — consistent recovery is what makes interval training productive rather than random.

Not Warming Up Properly

I’ve seen runners at Parkrun start sprint intervals with zero warm-up. That’s how you pull a hamstring. Program a 10-minute warm-up into your workout structure and your watch won’t let you skip it. The warm-up should include easy jogging building to moderate pace, plus some strides (4-6 × 15-second accelerations) to prime your muscles.

Running the Same Session Repeatedly

If you do 6 × 400m every Tuesday for three months, your body adapts and stops improving. Vary your intervals — change the distance, pace, recovery, or number of reps every 2-3 weeks. Your watch makes this easy because you can save multiple workouts and rotate through them.

Best GPS Watches for Interval Training in 2026

If you’re shopping for a watch specifically for interval training, these are the ones that handle it best.

Budget: Under £100

  • COROS PACE 3 (about £90 from Decathlon or Amazon UK) — best value interval watch by a mile. Structured workouts, pace and HR alerts, excellent battery life, and the app is simple. If you’re on our list of best running watches under £100, this tops it.
  • Polar Ignite 3 (about £95 when on sale) — strong HR accuracy from the optical sensor, good guided workouts

Mid-Range: £150-300

  • Garmin Forerunner 265 (about £250) — AMOLED display you can read in sunlight mid-sprint, excellent structured workout support, PacePro for pacing guidance, huge training community
  • COROS APEX 2 (about £200) — more rugged than the PACE 3, adds maps, better build quality. Interval features are identical.

Premium: £400+

  • Garmin Forerunner 965 (about £450) — the full package. Maps, music, advanced training metrics, touchscreen + buttons. If you want one watch that does everything.
  • Polar Vantage V3 (about £430) — best-in-class heart rate accuracy, dual-frequency GPS, AMOLED display, built-in running power

For most runners doing intervals 1-2 times per week alongside easy runs, the COROS PACE 3 gives you everything you need at a fraction of the price. The more expensive watches add features like maps, music, and advanced training load analysis — nice to have, but not essential for interval work.

Frequently Asked Questions

How often should I do interval training? For most recreational runners, 1-2 interval sessions per week is the sweet spot. Space them at least 48 hours apart and fill the gaps with easy runs. More than 2 hard sessions per week increases injury risk without proportional fitness gains. Quality matters more than quantity — one well-executed interval session beats two sloppy ones.

Can I do intervals with any GPS watch? Most GPS watches priced above £60-70 include some form of interval timer or structured workout feature. Very basic models may only have a simple interval timer (work/rest beeps) without pace or HR targets. For proper guided intervals with per-rep pace alerts, you’ll need a watch with structured workout support — Garmin Forerunner series, COROS PACE or APEX, Polar Pacer or Vantage lines all do this well.

Should I use pace or heart rate for interval targets? For short intervals (under 3 minutes), use pace — heart rate lags too much to be useful during brief efforts. For longer intervals (3+ minutes), either works, but heart rate is better in variable conditions like heat, hills, or fatigue. Many experienced runners use pace as the primary target with a heart rate ceiling as a safety check.

Do I need to run intervals on a track? No, though a track makes pacing easier because it’s flat and distances are precise. You can run intervals on roads, trails, park paths, or anywhere GPS signal is reliable. Avoid running intervals on busy pavements (too much dodging) or rough trails (injury risk at speed). A flat canal towpath or quiet park loop works perfectly.

My watch says my VO2 max went down after intervals — is that normal? Some watches recalculate VO2 max after every run. If your interval session was particularly hard and your pace-to-HR ratio looked inefficient (high HR for moderate pace during recovery jogs), the algorithm might temporarily lower your estimate. Look at the trend over weeks, not individual sessions. A single workout doesn’t meaningfully change your fitness.

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