High Intensity vs. Low Intensity: Many people have asked me which is better, working out at low intensity or high intensity workouts. To add to the confusion, machines in fitness facilities refer to the low intensity as “fat burning” and high intensity as “cardio training”. However this is misleading because you actually burn more fat at higher intensities, unlike what the machines tell you. Let me explain in numbers. Remember, though, never workout more than you are in shape to do. Higher intensity workouts should be reserved for those who are already physically fit or have at least been exercising regularly for at least a few months.
LOW: 50% max Heart Rate = 7 cal/min
90% of those calories are burning fat tissue
HIGH: 75% max Heart Rate = 14 cal/min
60% of those calories are burning fat tissue
On the surface, it appears that you burn more fat tissue when working at a lower intensity (90% vs. 60% from fat tissue), but these numbers are misleading. Lets look at them another way.
Low Intensity Workout, 90% * 7 cal/min = 6.30 fat calories per minute
High Intensity Workout, 60% * 14 cal/min = 8.40 fat calories per minute
Once you do the math, you burn a greater amount of fat tissue calories from a high intensity workout than a low intensity workout (8.4 vs. 6.3).