You may have heard of this but weren’t sure what it means. Here’s our summary.
The Norwegian 4×4 is a method of Cardio Training where you perform 4 reps of 4 minutes of cardio, with a 3-4 minute rest in between. For example, you might run for 4 minutes, then rest for 3, then run for 4 again, rest 3, run 4, rest 3 and finish with your 4th 4 minute run. Or you might do this on the exercise bike, or the elliptical, the rower, or if you’re a complete maniac, the assault bike.
It doesn’t really matter which form of cardio you choose, but here’s the catch, you need to do it at a fairly high intensity. The kind of intensity where at the end of the 4 minutes you’re pooped and very happy to be able to have a few minutes rest.
Why has it become so popular? Because it has been shown to be INCREDIBLY effective. And the results of doing this for just a few months can last for YEARS!
One study showed that doing this protocol 3 times a week for 6 months yielded benefits that lasted 5 years later!
Some quotes:
Short-Term and Cumulative Effects
- VO2 Max Surge: Rapidly increases maximum oxygen uptake by 7% to 13% within 8 weeks of consistent training (2–3 times a week). [1, 2]
- Cardiovascular Remodeling: Enhances stroke volume (blood pumped per heartbeat), strengthens the heart muscle, lowers resting heart rate, and reduces blood pressure. [1, 2]
- Brain Health: Stimulates superior structural and functional improvements in brain regions like the hippocampus compared to steady-state zone 2 cardio.
Long-Term Effects (Over 5 Years)
- Retained Cognitive Protection: Research on older adults completing a 6-month high-intensity interval training 4×4 intervention showed that the structural brain benefits and enhanced hippocampal function were largely preserved when tested 5 years later, even if participants dropped back to lower baseline activity levels. [1, 2]
- Cardiovascular Resilience: A sustained multi-year habit or baseline fitness built from the protocol contributes to long-term reversal of vascular and cardiac aging, keeping the heart structurally flexible. [1]
- Metabolic Memory: Sustained mitochondrial and enzymatic efficiency helps buffer against rapid age-related fitness decline, though cellular adaptations do partially regress if high-intensity work is completely abandoned for the entire 5-year duration. [1]
