Does cardio burn fat? Read this before your next gym workout

Cardio! Some people find it monotonous and fair enough because it can feel like that at times. But, is it good for you? Well, the unfortunate news is yes, it is good for you.

Whether you're pulling on running shoes or getting on an exercise bike, cardio is the easiest way to get exercise — running, walking, swimming, bike riding, rowing, dancing, and even cross-country skiing count as cardio exercises [1]. And, cardio is almost always low-cost or completely free.

What's more, cardio can be great for friendships: playing soccer, netball, tennis, hockey, and most team sports will involve a level of cardio where you can also be social (and competitive).

Enjoy gardening? That involves cardio too. Housework? You bet. Climbing stairs? Absolutely!

There are many peer-reviewed studies out there that can tell you the importance of cardio work for overall health. Cardiovascular exercise will lower blood pressure, regulate blood sugar, reduce asthma symptoms, improve energy levels, improve sleep quality and boost mood, and improve mental health, sharpness and overall outlook on life.

Even 20-30 minutes of moderate-intensity exercise, like walking, will vastly improve your overall mood [2].

But what about burning fat? Does cardio burn fat? And if so, will it burn calories in the most efficient way?

What is cardio exercise?

Cardio exercise, or aerobic exercise, involves getting your heart rate up and keeping it up for a prolonged period. High to moderate, continuous training will look different for everyone: your own knowledge of "moderate" might not be the same as, say, the moderate workouts of Usain Bolt or Cathy Freeman.

A simple measure of moderate-intensity exercise is the "talk test": you’re at the right level if you’re exercising hard enough to break a sweat, but can still comfortably hold a conversation.

Is cardio good for fat loss?

In short, yes — any type of exercise is good for fat loss. But the bigger and more pertinent question is whether or not it is the most effective way to burn fat.

What is the difference between weight loss and fat loss?

Lots of weight loss programs out there will claim to help you lose weight quickly and easily using cardio as your exercise tool. But, this is not particularly helpful for your body if you're making significant lifestyle changes. That's because weight loss is different to fat loss.

Weight loss refers to a decrease in your overall body weight, whereas fat loss refers to weight loss that occurs specifically from losses in fat mass. Sure, you will lose weight if you lose fat, but that's not all you will lose if you focus solely on weight loss.

A period of high-intensity cardio exercise will burn calories, right? Yes. Burning calories, combined with a calorie-deficit diet, will certainly lead to weight loss.

However, the loss of weight could also involve a loss of muscle mass and water.

A loss of muscle mass may happen when you're first on a weight loss journey, but it can be unhealthy for your overall health. Maintaining some muscle has benefits, such as regulating healthy blood sugar levels, maintaining healthy fat levels, and controlling inflammation.

Additionally, the more muscle you have, the more calories you burn at rest.

So going all in on cardio and no strength training isn't just boring: it's inefficient. Strength training builds lean muscle, increasing metabolism and decreasing fat — and the more muscle you build, the more calories you burn in your downtime.

What are the benefits of cardio?

Where do we begin? Cardio offers an enormous list of benefits for your physical, mental, and emotional health. Let us count the ways.

High-intensity interval training (HIIT) is one of the most effective workouts for fat loss, cardiovascular health, muscle development, blood pressure, lung health, and mental health [4]. It actually changes us on a molecular level.

HIIT boosts the number of proteins in skeletal muscle that are essential for energy, metabolism, and muscle contraction [5].

And the best part? It's quick: 30 minutes of high-intensity exercise, 3 times a week, will increase your energy, strengthen your mood, and decrease the likelihood of developing diabetes and other illnesses [6]. Combining weight training and HIIT is the gold standard of fat burning.

But you don't have to stick to HIIT. When it comes to moderate or even low-intensity exercise, like going for a simple walk, taking a dip in the ocean or pulling out weeds in the garden, you'd still be acing it with your health even if it's gentler than HIIT.

And look: you won't lose as much fat as you will if you do HIIT exercise. But, any physical activity will be great for your body and your brain. As long as you're working major muscle groups, eating a healthy diet, and finding the time to do it all in your busy life, you'll be reaping the benefits [8].

Benefits of cardio

High, moderate and low cardio workouts can help:

• Increase your stamina, fitness, and strength
• Increase your energy throughout the day
• Boost immunity
• Reduce the risk of high blood pressure, type 2 diabetes, and metabolic syndrome
• Reduce the risk of osteoporosis
• Help manage chronic illnesses like arthritis and even endometriosis and other inflammatory diseases [7]
• Boost lung health
• Boost mood and general mental health, reducing instances of depression and anxiety

How is fat burned?

Our bodies have been working hard for millions and millions of years to survive, and storing fat is an important component of human evolution.

Energy storage involved small packages of molecules called fatty acids, which were released into the bloodstream for use as fuel by muscles and other organs when there was no food available (or when a sabre-toothed tiger was chasing us) [8].

Today, with too much food, relatively safe living conditions and a distinct lack of sabre-toothed tigers around, humans are prone to excess storage of fat, leaving a considerable percentage of overweight and obese adults in Western civilisation.

When a person begins and maintains a new exercise regimen and limits calories, the body does 2 things to burn fat:

• It uses the energy stored in the fat cells to fuel new activity
• It stops putting away as much fat for future use

When you enter a new exercise rhythm, the brain will tell the body's fat cells to release the energy packages or fatty acid molecules to the bloodstream. The muscles, lungs, and heart pick up these fatty acids, break them apart, and use the energy stored in the bonds to execute their activities. The leftover bits are chucked out of the body through outgoing carbon dioxide and in our urine, where the body releases lots of waste.

Does fasted cardio burn fat?

Fasted cardio is, essentially, doing cardio exercises on an empty stomach. Why would anyone do this, you ask? Fasting has been touted as a highly effective form of weight loss and has risen to prominence in the diet discourse within the last decade.

Fasted cardio may offer some benefits if your primary goal is fat loss. Research supports that you'll burn more fat when you run in a fasted state than in a fed state.

One small study found that when people ran on a treadmill in a fasted state, they burned 20% more fat compared to those who had eaten breakfast. Why? When you don't have readily available energy from food, your body has to look elsewhere: i.e. fat cells.

However, fasted cardio isn't for everyone. Engaging in exercise before breakfast should be fine if you are drinking enough water, but if you a prone to dizziness then this might not be the best option for you.

What's the best form of exercise for weight loss?

When it comes to exercising for weight loss, experts recommend incorporating strength training and resistance training into your workout routines [3].

Cardio alone will help you lose weight and fat, but focusing on fat loss instead is the more effective route for your health.

The right amount of cardio for losing weight will vary from person to person, so speak to a doctor or health professional before embarking on a weight and fat loss journey, especially if you are entering menopause, have a chronic illness or disability, or if you're recovering from an injury.

For effective fat loss, incorporating a cardio workout (especially high-intensity interval training), a calorie-deficit diet, and some strength training will be better for your overall and ongoing health. And variety is the spice of life, right?

Other ways to approach weight loss

If exercise alone isn't cutting it, you might want to consider trying a holistic approach like Juniper's Weight Reset Programme.

With medication that suppresses your appetite and improves metabolic function as well as health tracking and lifestyle and habit changes, our UK clinicians, dietitians, and health coaches are here to help you find your confidence again.

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