When it comes to shedding pounds, the debate between different types of cardio is endless. Should you sprint? Should you walk? Here's what the science actually says about optimizing fat loss.
Understanding Fuel Sources
Your body primarily runs on two fuel sources: stored carbohydrates (glycogen) and stored fat. The intensity of your exercise determines which fuel source your body optimizes.
At lower intensities (like walking), your body burns a higher percentage of fat. At higher intensities (like sprinting), your body switches to carbohydrates because they can be burned faster for immediate energy.
LISS: Low-Intensity Steady State
LISS involves performing cardio at a consistent, low-to-moderate pace for an extended period (usually 30-60 minutes). Think of a brisk walk, a light bike ride, or an easy swim.
Pros: Very low impact, easy to recover from, burns calories without spiking hunger excessively.
Cons: Takes a long time to burn a significant amount of calories.
HIIT: High-Intensity Interval Training
HIIT involves short bursts of maximum effort followed by rest periods. For example, sprinting for 30 seconds, then walking for 30 seconds, repeated for 15 minutes.
Pros: Burns a lot of calories in a short time, increases "Afterburn" (EPOC) where you continue burning calories for hours after the workout.
Cons: High impact, stressful on the body, requires longer recovery time.
The Verdict? Do What You Can Sustain
Science shows that simpler is often better. While HIIT might be more "efficient" per minute, LISS is often more sustainable long-term. If you dread your HIIT workouts, you won't do them.
Recommendation: A mix is ideal. Try 1-2 HIIT sessions per week to boost metabolic capacity, and use LISS (like walking 8,000-10,000 steps daily) as your foundation for daily calorie expenditure.
Don't Forget Nutrition
No amount of cardio can out-train a bad diet. Cardio is a tool to increase your deficit, but your food intake is the primary driver of weight loss. Use our Calorie Calculator to ensure you're in the right zone.