
1x/week, do 4 mins run/swim at (95% HR) with 4 mins rest. Favour Intensity over duration.



VO2 Max is the maximum volume (V) of oxygen (O2) your body can absorb and use per minute. it's your body's "horsepower". Mortality Gap: Moving from the bottom 25% of fitness to the "Elite" bracket drops all-cause death risk by 5-fold. Low fitness is deadlier than smoking, diabetes, and heart disease combined. Intensity Wins: "Long Slow Distance" (jogging) improved VO2 max by just 1.8%, while HIIT improved it by 8.8%. The "4x4" Protocol: The highest ROI method is 4 mins at 90-95% HR, followed by 3 mins active rest, repeated 4 times.