Typically, fat burning settings are designed to get users to an aerobic zone where they are maximizing the percentage of calories that are being burned as fat. However, this is a little misleading if you are trying to burn the maximumpercentage of calories from fat through the oxidative/aerobic system possible.
Does that mean that if you worked out harder for 30 minutes that you would burn less fat? Probably not. If you are burning a total of 300 calories and 50% of those are fat calories, you burned 150 fat calories. However, if you work out at a high intensity and burn 500 calories, but 40% come from fat, you burn 200 fat calories. Make sense? The important thing to keep in mind when you exercise is that your body needs a good combination of fat, protein and carbs to keep the engine going. So exercising on an empty stomach first thing in the morning, or running for so long you run out of carbohydrates to burn, means you will tire quickly when your body turns to less efficient sources of fuel (fat and protein only). You may end up burning less fat in the long run.
So what is the best way to maximize fat burning?
You want to be at a really high intensity for short bursts, i.e. interval training. As explained here:
Training at such high intensities utilizes your body’s short-term energy systems: the ATP-PCr systems and the glycolytic system. The ATP-PCr system makes use of creatine phosphate stores in your muscle for high-intensity exercise lasting no more than 10 seconds. When the exercise bout lasts for up to 3 minutes, you are using mostly muscle glycogen, the stored form of glucose. When you consistently train at high intensities using these systems, you increase your capacity to work harder, thereby more calories and fat at a faster rate.
Interval training isn’t just more effective at burning fat and calories, it can be more fun.
- Exercise, Weight Loss, and the Fat Burning Zone (fitsugar.com)
- My take: Classes that BURN maximum calories (Part 1 of 2) (delfenriquez.com)
- 3 Reasons Why High-Intensity Workouts Are Essential (fitsugar.com)