Fitness Nerd Alert: How does exercise burn body fat?

5 min read

One of the primary reasons people choose to start an exercise routine is for weight loss. That may seem like a no-brainer, but ask anyone who’s really into fitness and you will get a spectrum of different answers — and with passion. Everything from aerobic exercise and burning calories to lifting weights and gaining muscle mass gets thrown out there, and that makes it difficult to navigate.

The truth about what it takes to trigger fat burning is that there’s a lot to unpack to give a clear answer. It’s also because the answer depends on a lot of different things, such as what your diet looks like, how old you are, and how long you’re doing exercises for. We can all agree that excess fat is bad and the health benefits are plentiful. But how do we get there?

But the answer doesn’t have to be as complicated as people make it. I mean, it should be straightforward, right? When does my body start burning fat? When can I see results? Those are good questions. So let’s dig in.

What Is Body Fat?

This is as good of a place to start as any. We talk about body fat as if it’s one thing. You get on the scale, see a number you don’t like, and then blame it on your fat. But the scale isn’t showing fat. It’s showing your total body weight. Fat, bones, muscles – all of it together.

So then it’s all about perspective, which we tend to lose when we step on the scale. For example, you have many different types of fat in your body, and they each play a role in your health. Some of this fat is necessary to keep you alive. But some of it isn’t and can harm you. 

You can tell the different types by their actual color in your body. Brown fat helps keep your core temperature up when you get cold, beige fat helps you burn calories, and white fat (the kind most of us think of when we think of fat) helps manage insulin and estrogen yet can cause a lot of health problems if too much of it is gained.

What Does It Mean to Burn Fat?

You can’t talk about burning fat without first talking about metabolism. That’s because metabolism is how the “burning” happens. It’s the 24/7 process that your body uses to convert your food and drink into energy. It’s also how calories and oxygen team up to release this energy, and keep your heart beating, your lungs expanding, and your blood circulating.

Yet when you consume fewer calories than your body needs, your body looks elsewhere for that energy source. That’s when it recruits fat to join the cause! And believe it or not, when you burn fat, you’re losing it in a couple of different ways. You lose it as water through sweat or urine, and you lose it as carbon dioxide when you breathe — yes, when you breathe. Yay science!

It’s also important to remember though that your body doesn’t just start burning fat the second that calories aren’t around to the job. For high-intensity exercise, your body primarily starts burning carbs first. This is because carbs are really easily broken down when you start aerobic exercises (such as walking or swimming) and anaerobic exercises (such as cycling or interval training).

That doesn’t mean intense exercise is worthless – far from it! But it does help to get a grip on what it takes to tap into fat burning versus simply expending energy stores.

How Can You Make The Switch to Burning Fat?

This is the million-dollar question. And in my experience, the switch happens around 30 minutes into your workout. This means that longer exercises will be better if you’re looking to shed pounds. Like I mentioned in the very beginning, there are hundreds of ways to get there and thousands of opinions. I’ll share my favorite types of exercise that get consistent weight loss results time after time.

High Intensity Interval Training

I already know what you’re thinking – didn’t I just say high intensity workouts don’t burn fat? If you read closer, you’ll notice I mentioned what your body uses first. With longer exercise, your body will start accessing fat mass. The trick here is to pace yourself with high intensity interval training (HIIT) workouts. The combination of intense exercise with low intensity strength training has a two-for-one effect. You get the calorie burn from the aerobic exercise and muscle breakdown that results in increased muscle mass.

Spin Classes

I’m a huge fan of spin classes. This low-impact exercise has a high-impact on your weight loss. Simply put, you burn more calories, strengthen your core, and improve cardio health with a solid spin class. It’s a great way to add variety to your exercise regimen if you ever feel stuck and unmotivated. This is still considered a high intensity workout but again the longer you train, the more fat burn happens.

Strength Training

Whether it’s through resistance training with bands or weight lifting with free weights, building muscle mass is a secret weapon if you want to burn fat. Moderate intensity workouts use fat calories for energy. This style of exercise doesn’t push your heart rate to its upper limit like cardio exercises can, but instead focuses on increasing your muscle mass. Muscles need energy, and your fat cells convert to glucose which your muscle can use for fuel.

Barre Classes

This low intensity exercise is a fantastic total body workout that can trigger fat loss and preserve muscle mass. The small, ballet-inspired movements require you to focus on posture and intentional movement. These workouts also improve balance and flexibility. Add this to your workout schedule, but don’t skip on the high intensity exercise for maximum fat loss effect.

How Do You Know If You’re Burning Fat?

All of these tips and know-how sounds great in theory. But how do you really know if any of this actually works? There are a few signs that your body is responding positively to your efforts:

  • You lose weight. Again it’s a no-brainer, but if you’re putting in the work, the scale will reflect it.
  • You look leaner. Like we mentioned before, a scale only tells part of the story. Fat burning shows itself in areas where you typically store fat: core, hips, legs, and shoulders.
  • Sugar cravings disappear. When your body transitions into a fat burning machine, you rely less on carbs for exercise energy (and everyday energy).

What’s your fat burning plan?

At McClure Fitness, we have a full schedule of classes that last around 50 minutes. They cover all levels of intensity, and are tailored to maximize fat loss and weight loss goals. Best of all, you get the direction and community support to make sure you finish strong every time you join us.