Myth: you'll burn off more fat if you work out at lower intensities versus higher intensities during cardiovascular activities.
Reality: all right, this is technically true, but you have to look at the total picture to comprehend why this would really work against you if you're attempting to slim down.
This info that I'm going to share with you is based on scientific research and is instructed in every exercise physiology college course.
If you're working out at a low intensity, say 50-60% of your maximum pulse, we're probably safe to say that more than one-half of the calories you're burning off come from fat (let’s suppose 60%), and the remainder (approximately 40%) come from sugar, or carbs, in your bloodstream and in your muscles. Bottom line, you burn a greater share of fat at this intensity level than carbs.)
In case you aren’t acquainted with intensity based on pulse, 50-60% of your maximum pulse is an easy pace, something you likely could sustain for a long time, perhaps hours.
When you're exercising at greater intensities (suppose 70%-80%), we're safe to state that most individuals are burning off a higher percentage of carbs than fat. Now, simply from this info alone, it may be easy for individuals to believe they're burning more fat at the lower intensities, correct?
The percentages are sure enough greater at the lower intensities. So you may see why so many individuals thought this was the better way to burn fat.
Well, let’s have a closer look at what is truly occurring. Let’s suppose you've a choice to work out at lower or higher intensity, and let’s presume two additional things: 1) among your fitness goals is to drop off body fat and 2) you've a particular amount of time to do your aerobic training; for the sake of this illustration, let’s suppose you only have a half-hour. Let’s utilize a real world example. We’ll call her Joan. One day, Joan works out at 60% (low intensity) of her maximum pulse on the treadmill and she burns off 150 calories. If we may safely say she's burning about 60% of her calories from fat, then she burned off about 90 of those calories from her fat stores. And, if the other 40% of calories burned off came from carbs, then she burned 60 calories from carbs.
The following day, Joan does a higher intensity (80% max pulse) exercise on the treadmill (you have to compare utilizing the same mode of exercise), and she burns 310 calories in a half-hour. If 40% of those calories hailed from fat and 60% from carbs, then she burned 124 calories of fat, and that leaves 186 from carbs.
So, while Joan burned a greater portion of calories from fat with a lower intensity exercise (60% vs. 40%), her absolute value of calories burned off of fat was better in the higher intensity exercise (124 fat calories) versus the lower intensity exercise (90 fat calories). Do you understand why this is a myth and where it may have come from?
Let me make this truly simple. In terms of dropping off body fat, it is not the absolute number of fat calories that counts as much as the absolute number of calories altogether. To exercise off one pound of body fat you have to burn an additional 3500 calories, whether you accomplish it with low intensity or high intensity. I’m sure you are able to see that if you're a busy individual, it pays to get fitter so that you may burn more calories in less time.
However, there's a crucial point about fat burning and intensity level. It has to do with "time to fatigue”. Fatigue may impact how many calories you burn. Let me explain.
When Joan is walking at 111 bpm, or 60% of her maximum pulse, if she had the time, she could continue going and going, for a really long time without getting tired. But when she's moving on the treadmill at 148 bpm (80% of her maximum pulse), after a half-hour, she's dog-tired! She's very little energy left. She wasn't fit enough to do that.
Let me explain how fat and carbs get into play here. When you're chiefly utilizing fat as an energy source, as in the case of Joan exercising at 111 bpm, a lower intensity for her, your body may continue to manufacture energy without running out of it. Put differently, it will take a while to tire. However, when you work out at greater intensities, you utilize a bigger percentage of carbs. As the percentage of carbs increases, the sooner you'll tire.
Why is this crucial? I want you to fully comprehend how fat and carbs play a role in exercise and weight loss. Firstly, fats and carbs are equally crucial as energy sources when it comes to exercise.
Secondly, one supplies slow, long-term energy (fat) and the other supplies quick and powerful energy (carbs). Intensity of work out impacts which energy source will prevail over the other.
Thirdly, your intensity level ought to be based on your goals. If your goal is to burn off as many calories as possible in the quickest amount of time, you need to exercise closer to the top end of your capacity.
If your goal is to exercise for a lengthy time period and optimize the number of calories you burn, you'll need to pace yourself. If you merely wish the health benefits, you need to accumulate half-hour a day of activity, which may include exercise and general activity.
Note that the better way to avoid burn out but sustain high levels of fitness and calorie burn is to use interval training, interchanging short bursts of higher intensity training with longer periods of lower intensity training.
Finally, don't forget that the first goal of any exercise program is consistency. It's crucial to begin at your current fitness level and slowly progress in little increments.