You will find a graph on many cardio equipments is to tell you the desired heart rate you'd have for the cardiovascular or fat burning training. The way the industry comes up with these calculations is usually by subtracting your age from 200 bpm while 60% of the same number for burning fat. They reason that the training at lesser intensity uses fat for energy while training at a higher intensity will use glycogen or carbohydrates. It seems very scientific and convincing but sadly it is not true.
The way the body burns energy is too complex that can be manipulated by the simple shift in heartbeats. You should be aware that when you exclusively burn fat is the time when you sleep. The problem is that when you're asleep you're not very active, so the overall consumption of energy is low. Now during the day when you are active your body consumes fat and carbs for energy. The previous reasoning is not all false because in low-intensity cardio burns more calories through fat as compared to high-intensity interval training, however, in the latter technique the world consumption of calories is much lower.
Regardless of this complexity interval training is good for burning fat especially when excess post-exercise consumption (EPOC) also known as the oxygen that is higher with high intensity compared to low-intensity cardio workout. The gym in Susie asked refer to this as the "afterburn effect" it takes care of additional 50 cals burned during the 24 hour period after your done with your cardio. This might not seem like too much but it can be for professional athletes that are usually very lean, and every ounce of energy and calories is crucial.
There is some scientific evidence proving that this type of cardio workout is more helpful in burning fat, so the question is the low-intensity cardio useless?
To answer this, there are two scenarios when low-intensity cardio is the best thing you can achieve. After your workout session with weights and while you're on a low-carb diet. The mechanics behind this is that when you're done lifting weights your glycogen reserves are low more free fatty acids are running in your bloodstream. So a low or medium intensity cardio is extremely effective to burn this off.
Secondly, anyone who is on a low-carb diet is already low on glycogen, and any HIIT cardio workout will likely cause muscle loss. A work out at about 100 to 120 bpm is great for burning fat without losing muscles. The reality is that most of you can easily perform a medium intensity cardio for a longer duration instead of an HIIT so the result is both burn approximately the same number of calories
You should choose according to your personal preference. For instance, if you have a time crunch you should go with HIIT cardio workout but if you have plenty of time and your weight training game is already strong you should stick with medium intensity cardio. And please don't be a fool for the myth that it would take 20 minutes for your body to start tapping into the fat storage. Noted somewhere that energy production is a 24-hour cycle and if a someone tells you that there is a magic switch in your body that turned on after 20 minutes to burn fat for the energy is lying. In the end, it all comes down to a very basic equation that it's all about the overall intake versus the energy expenditure.
Here's a tip from the pros, it is important to put variety in your cardio. You should always be looking forward to switching between bike, treadmill, and a Stairmaster. During the summer season try to work outside and focus in the cardio as much as possible. Put on some nice music in your earphones and the additional sun exposure will help you achieve better results.
