Fitness coach Dan Go is highlighting a workout protocol, called the Norwegian 4×4 workout, that could help dramatically improve heart health and cardiovascular resilience.

“This workout reduces the age of your heart by 20 years,” Go posted in a post on X. “There’s a workout that’s been proven by science to reduce the age of your heart by 20 years. It’s called a Norwegian 4×4 and in this video, I share what it is and also how to apply it to your body.”

The Norwegian 4×4 workout involves four 4-minute intervals of vigorous exercise at 85–90% of maximum heart rate, separated by 3-minute rest periods at 50% of maximum heart rate. Research from the Norwegian University of Science and Technology (NTNU) has shown that this high-intensity method can significantly boost VO₂ max, lower cardiovascular risk, and even lower biological heart age by up to two decades.

Dan Go, known as Fit Founder, is a fitness entrepreneur and performance coach who helps busy executives and entrepreneurs optimize their health, body composition, and energy through simple, sustainable fitness strategies.