05/08/2026
If you’re short on time but want one of the most effective ways to improve your cardiovascular fitness, this is the protocol to know.
The Norwegian 4×4 involves:
• 4 minutes working at around 85–95% of your maximum heart rate
• 3 minutes of easy recovery
• Repeat 4 times
Research has shown this style of training can significantly improve VO₂ max – one of the strongest indicators of long-term health, fitness and longevity.
You don’t have to be an athlete to benefit. The intervals can be done on a bike, rower, uphill walk, treadmill or any cardio equipment where you can safely raise your heart rate.
Work hard. Recover well. Repeat consistently.
Save this post for your next cardio session and send it to someone who says they “don’t have time” to get fit.
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