I have written about cardio before and compared it to weight training. But in this article I want to talk about cardio as a standalone exercise. Cardio has been proved to provide health benefits mainly by strengthening the cardio-vascular system of your body.
What really happens is that after your cardio session, your heart becomes stronger and pumps higher volume of blood with each stroke, this means you need less heart beats per minute to supply oxygen to your body. Resulting in low resting heart rate.
The other thing which happens is that the increased blood circulation causes all of your bodies cells to get an adequate supply of oxygen and they are in ‘top condition’. Yes, if you are inactive all your body cells are probably not getting enough oxygen!
The Fat Burning Zone in Cardio
You must have seen the marking on most cardio equipment where it indicates the ‘fat burning zone’. The fat burning zone is defined as 55% to 65% of your Max Heart Rate. This was found to be the most optimal range for maximum fat oxidation (Ref1).
When you start running ‘faster’ you enter the ‘cardio zone’ and sure your oxygen capacity is increased and you have all the heart benefits of cardio, but you will also suffer from muscle mass loss (Ref2). Muscle mass loss results in lowered metabolism. This is sadly the opposite of what you want to achieve.
Even endurance athletes now include strength training in their workouts to preserve muscle mass and to prevent injuries.
Getting back to the fat burning zone, the target heart rate for this zone is not very high. You can easily reach this when you do your morning /evening walk.
Does this mean that you can burn fat by only walking?
Yes, but you would have to do hours of it!
This is because your overall calorie expenditure is low at this pace. You burn fat but not too much of it.
It takes 20-30 minutes of intensive effort to near the end of body’s glycogen stores. But if you are walking, your glycogen stores can last for hours.
So unless walking is a source of your livelihood, there are better ways to burn that fat fast.
THEN, HOW TO LOSE FAT FAST?
1. HIIT: With all the benefits of traditional cardio, HIIT will burn more calories in shorter amount of time. Moreover, it will increase your metabolism unlike low intensity cardio. HIIT also directly targets abdominal fat or belly fat by increasing fat oxidation resulting from release of the fat burning pedals of your body – Growth Hormone, Adrenaline and Glucogon. (Ref3)
2. Less Rest between your Lifts: Less rest will increase your oxygen requirement and increase post exercise calorie burn, in other words it will further elevate your metabolism post your weights workout. Reduce the rest interval only till your performance of the next set is not affected by it.
3. Intermittent Fasting: Utilises fat burning hormones more efficiently (Ref4). Undeniably one of the smartest ways to lose fat.
4. Low Carb Diet: Proven by research to reduce the most fat when accompanied by a calorie restrictive diet.
There are many smart ways to lose fat while preserving or even adding to your lean mass. Use them to improve your body composition and conditioning.
Related: Find out your ideal weight and your target body fat for a defined mid-section.
Ref1: Daniel R Moore et al. Beyond muscle hypertrophy: why dietary protein is important for endurance athletes. Applied Physiology, Nutrition, and Metabolism. 10.1139/apnm-2013-0591
Ref2: Achten J, et al. Optimizing fat oxidation through exercise and diet. Nutrition. 2004 Jul-Aug; 20(7-8):716-27
Ref3: Boutcher SH. High Intensity Intermittent Exercise and Fat Loss. J Obes 2011; 2011: 868305
Ref4: Azevedo FR, et al. Effects of Intermittent Fasting on metabolism in men. Revista da Associacao Medica Brasileira. Vol 59 (2); Mar-Apr 2013; 167-173