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Norwegian 4x4 Timer

4 hard rounds · about 38 min

READY

WARM-UP · 10 min

Next: Hard 4:00

Time left in this interval

10:00

Whole workout

0% done

0:00 of 38:00

0:00 elapsed0%

Tip: press Space to start or pause.

Whole workout

0:00 elapsed · 38:00 left · 0%

  1. W warm-up, upcoming

  2. H1 hard, upcoming

  3. S1 slow, upcoming

  4. H2 hard, upcoming

  5. S2 slow, upcoming

  6. H3 hard, upcoming

  7. S3 slow, upcoming

  8. H4 hard, upcoming

  9. C cool-down, upcoming

  • H = Hard (stripes)
  • S = Slow (dots), C = cool-down
  • W = Warm-up
  • Solid + ✓ = done · Bold outline = now · Dashed = coming up

Sound

  • Hard starts: a bright, buzzy two-note sweep that rises. Slow starts:a bright two-note "ding-dong" that falls. Both are loud and high enough to hear while you are working hard.
  • For the last 10 seconds of every interval you get one beep a second: higher and sharper when a HARD interval is next, lower (but still clear) when a SLOW interval (or the finish) is next.
  • Phones on silent mode may mute browser sound. The big on-screen countdown and colours work either way.

Minute alerts

For both hard and slow intervals. You can change these while the timer is running.

Screen flashes are skipped automatically if your device asks for reduced motion (the tones still play). Tones follow the Sound switch above. When both are on, the last-minute warning replaces the 1-minute milestone at that moment. The warm-up only gets the last-minute warning, to keep it quiet.

Settings · 38 min total

Warm-up

0 = skip the warm-up

10 min

Hard interval

Default 4 min

4 min

Slow interval

Default 3 min

3 min

Hard rounds

Default 4

4

Cool-down length

Default 3 min, same as slow

3 min

Settings, alert switches and sound choices are saved on this device in one small cookie (n4x4_prefs, kept for one year) and in local storage. It is not used for tracking or ads.

What is the Norwegian 4x4 method?

The Norwegian 4x4 is a style of interval training. After a warm-up, you do four hard efforts of 4 minutes each. Between them you move at an easy, active pace for 3 minutes. With a 10-minute warm-up and a final slow interval as a cool-down, the whole session takes about 38 minutes.

  • Hard intervals (4 min): a demanding but steady effort, commonly described as roughly 85–95% of your maximum heart rate.
  • Slow intervals (3 min): active recovery. Keep moving gently, commonly described as roughly 60–70% of your maximum heart rate.

Maximum heart rate and fitness differ a lot from person to person, so heart-rate zones are only a rough guide. This timer only keeps time and plays sounds: it does not measure your heart rate and does not know what is right for you. You can use it with running, cycling, rowing, brisk uphill walking or another activity you are used to.

Health disclaimer: This tool is for general information and timing only. It is not medical advice and does not promise any result. High-intensity exercise is not suitable for everyone. Talk to a doctor or other qualified health professional before you start, especially if you have a health condition, take medication, are pregnant or have not exercised for a while. Stop straight away if you feel unwell, dizzy, faint, or have chest pain or unusual shortness of breath, and get medical help if you need it.

How to use it

Interval timer for a Norwegian 4x4 workout: warm-up, four 4-minute hard intervals with 3-minute slow recoveries, progress bars, a 10-second countdown and distinct sounds.

  1. 1Check the settings if you like (warm-up 10 min, 4 rounds of 4 min hard and 3 min slow are the defaults). Set the warm-up to 0 to skip it.
  2. 2Press Start (or the Space bar). Turn your sound on and check the volume with the test buttons first.
  3. 3Follow the big label and colour: red GO HARD, blue GO SLOW. The last 10 seconds of each interval show a countdown and play a beep each second.
  4. 4Use Pause, Skip interval or Reset whenever you need to. Keep this page open while you exercise; on supported phones the screen is kept awake.

Always check with a doctor before starting high-intensity exercise, and stop if you feel unwell. This timer is not medical advice.

🌿 Wellness & Health⚡ Productivity

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