The “fat burning zone” is around 60-70% of your maximum heart rate, which is the zone your body burns the highest percentage of fat. Surprisingly, the fat burning zone is not necessarily ideal to torch stubborn fat or lose weight! The reason is simple – at higher intensity you’ll burn more calories per hour, even if the percentage of fat burned is slightly less. This means that slowing down your brisk walks just to stay in the fat burning zone is usually a mistake. Don’t discount leisurely walks either, which are great for physical and mental health.
We’ll cover the fat burning zone – both myth and reality. You’ll learn why lower-intensity walking really does have amazing benefits, but why higher-intensity walks might be just what you need to hit your goals.
What exactly is the Fat Burning Zone?
If you’ve ever used a treadmill or elliptical machine, you’ve probably seen various heart rate zones on the readout. Simply speaking, the “fat-burning zone” is an intensity or heart rate level where your body is burning more fat than carbohydrates. According to Self, it’s generally listed as 55-70% of your MHR (maximum heart rate). If you don’t have a heart rate monitor available (most don’t), that would be about a 6 out of 10 in terms of exertion.
Why do people target this zone?
It sounds like burning a higher percentage of fat is the best way to get rid of stubborn belly fat and get more fit, right? It’s actually not so simple. The human body relies on glucose for energy. The two primary sources of this glucose are carbohydrates and fats. For these two elements to turn into glucose, they require oxygen. Carbs are easier and faster for your body to break down and use as energy, while fats are more complex and require more time and oxygen to break down. HowStuffWorks has a great explanation of how your body breaks down nutrients into energy.
Your body requires energy, even when you’re not moving, to keep your heart pumping, lungs breathing and everything else you need to stay alive. As you move and exercise, your body needs even more energy, more urgently. This means that the harder your body works, the more it shifts to breaking down the comparatively easier and faster carbohydrates for energy. According to US news, your body may be getting 60% of its energy from at low-intensity exercise and 35% or less at higher intensities.
Why is this misleading?
While it’s true that the body utilizes a higher percentage of fats with low-intensity exercises, this doesn’t make slow workouts the magic pill for weight loss. Why? Targeting the “fat-burning zone” misses important points – cardio and total calories are more important than the percentage of fat burned.
Cardio & calories vs fat burned
If you’re walking at a relatively slow pace, you may be burning a higher percentage of fat but you’ll be burning fewer calories and getting less of a cardiovascular workout for your heart and body. This doesn’t mean that you should never walk slowly, but it does mean that slow walking isn’t necessarily better for you just because you’re in the “fat-burning” 50-70% of your MHR zone.
Are you walking for cardio?
If you’re walking to get a cardio workout, getting more intense helps you hit the moderate to vigorous-intensity exercise that you need for maximum benefits. While you may also want to burn fat and calories, walking intentionally slower will reduce the effectiveness of your workout.
Are you walking for weight loss?
If you’re looking to lose weight or walking to burn fat, you want to consider calories burned rather than the percentage of fat burned. While fat can be broken down into energy, unused carbs can be converted to fat as well. Otherwise, we could eat sugar all day and never gain weight. Both carbs and fat burnt contribute to the total calories lost. Hence working out at a slow and steady pace for thirty minutes won’t cause you to burn more fat in the long run than someone who walked at a brisk pace. This means that if you’re looking to lose weight by walking, more intensity will burn more calories and help you lose more fat in the long run.
Get more intense in other ways
Of course, you don’t have to get super intense. You can try longer walks instead. If you can manage to get more intense, adding intervals, incline walking or climbing stairs can get your heart pumping and burn more calories.
Intervals, or high intensity interval training (HIIT) can give you the best of both worlds. You’ll do bursts of faster walking, with slower walking in between to recover. With interval training, you’ll get more steps in less time, without having to jog or walk very fast the entire time. With HIIT, your heart rate will rise and fall depending on the intensity, so you’re not at the maximum level for the entire walk.
Percentage versus total numbers
It might surprise you to know that you burn the highest percentage of fat when you’re not doing anything at all! When you’re at rest, as much as 85% of the calories you burn come from fat. Thought that sounds great, 85% of a small number is still a small number and you don’t burn many calories at rest.
The harder you exercise, the more calories you burn overall. You might burn 200 calories in an hour from walking slowly, with 120 of those coming from fat. Walk very quickly, or jog, and you might get that calorie burn up to 300 or 400 calories burned per hour. That’s about 105-140 calories of fat burned, plus an additional 100-200 calories of carbs.
Of course, not everyone walks for weight loss and not everyone likes to get intense. That’s why a long walk can be just as good as a short jog. There’s nothing wrong with walking in the fat-burning zone – it’s just not necessarily better for you than doing a more intense walk if you want to.
That doesn’t mean that low-intensity exercise is bad!
Not everyone enjoys jogging for fitness or walking at an intense pace. Low-impact, low-intensity workouts such as walking for fat loss are especially great if you’re starting out and not used to sustaining HIIT exercises. You’ll burn calories by walking and you’ll improve your cardio and fitness. The more steps you take, the fitter you’ll get and the more calories you burn. That’s true whether you’re getting more intense or less intense.
If you have health problems, physical limitations or dealing with an injury, low-intensity exercise in the fat-burning zone might be the perfect thing for you. Even if you’re a serious walker, pushing yourself every day will only increase your risk of injuries and cause burnout and overtraining. The fat-burning zone can be great even for serious athletes who want a rest day, or just don’t feel like getting intense on any particular day.
To wrap things up, the “fat-burning zone” is a real thing, but it doesn’t work the way that it might seem at first glance. The most intense “fat-burning zone” is when you’re at rest and burning almost all fat. If your goal is to get fitter or lose weight, you’ll want to do a more intense, brisk walk to maximize your fitness gains.
Still, walking at a more leisurely pace (ending up in the fat-burning zone) is great exercise and should be at least part of every walker’s walking routine. It’s just not a magic bullet that can solve all of your fitness needs.
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