Norwegian 4×4 Protocol
Four hard four-minute intervals separated by active recovery, with a full warm-up and cool-down.
Our editorial view of evidence, usefulness, cost, and ease of adherence.
How scoring worksThe short version
Quick protocol
Best for: Regular exercisers who already have a base and want time-efficient VO₂max work.
Do this in order
Protocol steps
- 0110 min
Warm up fully
Increase effort gradually and include two short pickups.
- 024 × 4 min
Complete four work bouts
Work hard at a pace you can maintain across all four intervals.
- 033 min between
Recover actively
Keep moving easily between work bouts.
- 045–10 min
Cool down
Move easily until breathing settles.
Keep the kit small
What you need
Curated picks, not an endless catalog.
Simple interval timer
Keeps the protocol repeatable without adding more screen time.
Use the timer you already own
The best starting setup is often your phone, watch, or gym clock.
Some product links may earn us a commission at no added cost to you. Recommendations are selected independently.
Context after the answer
Why this structure works
The useful part of a protocol is the dose you can repeat. This version deliberately starts conservatively, gives you a clear stopping rule, and leaves room to progress only after the routine feels stable.
Evidence labels describe the body of research behind the broad practice—not a promise that every person will get the same result. Where research is observational, indirect, or limited to a specific population, we treat that as a constraint rather than filling the gap with certainty.
Safety note
Know when the protocol is not the move.
This is demanding exercise. Build a base first and seek clearance when cardiovascular risk or symptoms are present.
Read the evidence
Sources
Reviewed for this protocol
Editorially reviewed · Last updated August 2026
