ExerciseExplorer
A woman climbing a grassy hill at a hard pace

Categories / HIIT & conditioning

Norwegian 4x4

Four 4-minute hard efforts with 3-minute recoveries.

Typical session40 min × 2/wk
Effort●●●●● Very hard
CostLow cost
EquipmentBasic kit
WhereOutdoors
SocialSolo or group
ImpactMedium impact
AgesTeens, Adults 18-49
CommitmentNeeds discipline

How to start

After a 10-minute warm-up, do 4 intervals of 4 minutes at a hard effort (about 85 to 95% of maximum heart rate) with 3 minutes easy between, then cool down.

How to progress

Start with 2 or 3 intervals, and build to 4. Do it once or twice a week.

What the evidence says

Evidence: limited

We found no trials of this particular format. A 2026 analysis of the Generation 100 study (500 people aged 70 to 77) found that those who kept up high-intensity training had the smallest declines in fitness over 5 years. It was an observational analysis within a trial and does not prove the intervals were the cause.

Take care: Four minutes at high effort is demanding. See a GP first if you have a heart or blood pressure condition. Avoid it when unwell.

Sources

12-week starter plan

Once or twice a week. Use a heart rate monitor or the talk test: you should be able to say only a few words.

0 of 12 weeks done

Tick each week as you finish it; your ticks are saved on this device only. Repeat a week if it felt hard. Weeks 4, 8 and 12 hold steady so you can settle. This is a general plan, not medical advice.

Add reminders to your calendar

Pick your days and time. You will download a calendar file that adds 12 weeks of reminders to Google, Apple or Outlook calendar.

Calories and weekly minutes

Enter your details for a rough estimate. Based on about 8 METs (Typical effort for this activity (estimated)). Real figures vary by 20% or more between people.

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0calories per week
0minutes per week
0% of the 150-minute weekly guideline

Tips and common mistakes

Tips

  • Use a hill, bike or treadmill with a steady incline.
  • Hard but controlled.
  • Eat and drink before.

Common mistakes

  • Starting too fast.
  • Not warming up.
  • Doing too many sessions.

Kit and cost

Low Approximate UK prices.

  • A heart rate monitor (optional)
  • A bike, treadmill or hill
  • Trainers

Frequently asked questions

What is 4x4?

Four intervals of four minutes hard, with three minutes easy between.

Is it good for older adults?

One analysis suggests high-intensity training helps maintain fitness, but check with a GP first.

How often?

One or two sessions a week.

Good for: Heart & fitness Endurance

Compare with similar options

Norwegian 4x4HIITTabataSprint Interval Training
Typical session40 min × 2/wk25 min × 3/wk4 min × 4/wk15 min × 3/wk
Effort●●●●●●●●●●●●●●●●●●●●
CostLow costFreeFreeLow cost
EquipmentBasic kitNo equipmentNo equipmentSome equipment
ImpactMedium impactMedium impactMedium impactMedium impact
Fitness neededModerate fitnessSome fitnessModerate fitnessModerate fitness
Evidencelimitedmoderatelimitedmoderate