Want to improve your heart health, boost VO₂ max, and get more out of your cardio in less time? In this video, I break down the Norwegian 4x4 Protocol — one of the most effective, science-backed interval training methods for improving cardiovascular fitness and longevity. As a cardiac sonographer and trainer, this is one of my favorite ways to help people strengthen their heart, improve endurance, and train with purpose. ❤️ What You’ll Learn: ✔️ What the Norwegian 4x4 protoco