You’ve probably heard of fasted cardio if you’ve done much research on weight loss and exercise. It’s all over the place, and as it turns out, not eating before your workout could have some significant benefits.

What are fasted cardio benefits? And do you need to do it? This guide will walk you through everything there is to know about fasted cardio so that you can make an informed decision as to whether or not it’s right for you!

What Is ‘Fasted Cardio’?

Fasted cardio is a way of exercise in which one exercises on an empty stomach. It may also be referred to as early morning fasted cardio or morning fasted workout. The idea behind this is that when one exercises on an empty stomach, they burn more fat than they would if they were eating beforehand. For most people, this type of exercise can be done for 30-60 minutes, but it may vary based on age and fitness level. 

Some studies[1] have shown that fasted cardio program (or routine at home) combined with a low-calorie diet has been shown to help reduce belly fat.

The Basics Of Fasted Cardio Workouts

Fasted Cardio Workouts

The best way to do fasted cardio workouts is with a fasted cardio routine at home. Of course, you should be careful not to overdo it but fasted cardio has many other benefits. For example, your muscles can burn more fat, and you will feel more energized with a morning fasted workout.

According to Natasha Trentacosta[2], a sports medicine specialist, M.D., of Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, for your workout to be ‘fasted,’ you should go for eight to twelve hours without food. Depending on how quickly your digestive system operates and how much food you consume at your last meal, it might take three to six hours.

According to a sports medicine dietitian at The Ohio State University Wexner Medical Center, a fasted state can also be achieved in the afternoon or later in the day if you’ve skipped lunch or do intermittent fasting.

The Best Pre-Workout For Fasted Cardio

The best pre-workout for fasted cardio would be caffeine, l-carnitine, and branched-chain amino acids (B.C.A.A.s). These supplements should be taken two hours before a workout. Drinking 16 ounces of water will also help with hydration. A fasted cardio program can last anywhere from 10 minutes to an hour, depending on your fitness level. Making your pre-workout for cardio at home with a few inexpensive components from your neighborhood health food store or a reputable online distributor is the best option.

Research / Science Behind Fasted Cardio

The experts say that fasted cardio is an effective way to lose weight and build muscle, but it’s essential to work out on an empty stomach so that the body burns fat for fuel. If you’re following a fasted cardio routine at home, ensure you eat within an hour of working out. 

Otherwise, your body will convert protein in your muscles into glucose and use it as energy, and drinking plenty of water before and after the workout is also a good idea. The science behind fasted cardio says it’s one of the most efficient ways to get leaner and stronger because you’ll burn fat instead of sugar. 

The morning fasted cardio program may be difficult for some people because they’re used to eating breakfast first thing in the morning. However, if someone does find themselves waking up early enough to do a morning fasted workout, they can save those calories later in the day (which would typically be consumed with breakfast).

Types Of Fasted Cardio

Types Of Fasted Cardio

Two types of fasted cardio exist. The first type happens when your liver is low on glycogen, yet the muscle glycogen stores are still decent. You could achieve this goal if you had an early dinner the previous day and exercised in the morning before breakfast.

The second type is when you go to exhausting your muscle glycogen stores and purposefully not replacing them, such as by engaging in intensive exercise for a week while consuming the fewest carbohydrates possible. Again, only elite and advanced athletes should typically drastically reduce their carbohydrate intake.

Benefits Of Fasted Cardio Workout

  • The fasted cardio program is much more comfortable because your stomach isn’t full. It’s much easier for you to breathe, and it’s less likely that you will feel nauseous or lightheaded.
  • It also enables your body to burn more fat because when your insulin levels are low, it relies on fat as its primary energy source instead of carbs.
  • Fasted cardio spares you the need to prepare, eat, and digest a meal in advance if time is of the essence.
  • Fasted cardio helps with weight loss and provides many other health benefits, including increased athletic performance and lower blood pressure. This type of workout may be correct for someone who wants to lose weight and get healthy!
  • Your body will adjust to burning fat for energy more effectively.
  • For those looking to burn fat and get healthier, fasted cardio could be just what they’re looking for. In addition, one must factor in the convenience factor–fasting allows one to work out without worrying about eating beforehand.

Fasted Cardio Vs. Non-Fasted

While the two are not entirely different, there is a difference. Generally, fasted cardio is done first thing in the morning on an empty stomach, and non-fasted cardio is done later in the day after breakfast or lunch. The main difference between the two is that you can burn more fat by doing fast cardio first thing in the morning because your body’s insulin levels are low. With lower insulin levels, your body will start burning stored fat for energy instead of glucose from carbohydrates.

Risks Of Fasted Cardio

According to fitness expert Marc Dionne fasted cardio will kickstart your fat-burning engine by providing energy from ketones and body fat. A fasted cardio program may work for you if you’re looking for a way to burn calories and lose weight.

Risks Of Fasted Cardio

A fasted cardio routine at home is doable for anyone who can’t get out in the morning. The risks of implementing fasted cardio are that it could cause fatigue or dizziness, and if not done properly, this type of exercise might also lead to a lack of sleep or constipation.

Marc Dionne also warns that you should not engage in heavy lifting on an empty stomach because this will inhibit protein synthesis and make it harder for muscles to grow. Experts advise that when undertaking fasted cardio, water intake should be increased significantly as dehydration during workouts increases the risk of heat stroke.

In addition, shaking, dizziness, and passing out[3] might be some of the side effects of doing fasted cardio.

Are Fasting Workouts Effective?

According to some professionals, fasted workouts might prove effective if you’re looking to burn fat. A 2006 study published in Medicine and Science in Sports and Exercise found that muscle proteins were broken down during exercise when participants had not eaten for 12 hours beforehand. The researchers also noted that this effect was more pronounced after a 40-minute workout than it was after a 20-minute workout. Dr. Trentacosta explains that when you don’t have immediate access to energy from meals, your body must look elsewhere.

In addition, the certified strength coach and chiropractic doctor Allen Conrad explains that fasted cardio is effective for people working out regularly to help the body burn stubborn fat.

Does Fasting Burn Fat?

Your body can burn fat if you fast for a set period each day or consume only one meal a couple of days a week. Additionally, there are some health benefits, according to scientific findings.

It’s practical to lose weight without calculating calories by implementing intermittent fasting. Numerous studies indicate that it can aid in weight loss and abdominal fat reduction.

However, according to the board-certified specialist in sports dietetics, Meghann Featherston, the body might not automatically burn fat instead of burning glucose in the fasted state. Instead, the body might turn to protein. So, according to another research[4], fasting might negatively impact the volume and intensity of training, thus hindering your performance and stopping body fat burning.

Who Should Avoid Fasted Cardio?

should avoid fasted cardio

Do not do fasted cardio if you are pregnant or breastfeeding. Also, do not do fasted cardio if you have diabetes, and take insulin, low blood sugar, or medication for diabetes. Additionally, brand-new exercisers should avoid fasted cardio; getting to know your body properly should be your first step.

How Long Should A Fasted Cardio Session Be?

fasted cardio session should last between 20 and 30 minutes, depending on your fitness level. It will depend on how long you get your heart rate up and keep it there and how long you can sustain a high-intensity workout. 

According to fitness trainer, Sarah Craske fasted cardio should be moderate, not more than an hour.

What To Eat After Fasted Cardio?

What you eat after a fasted cardio workout will depend on your goals. If you’re looking for weight loss, try eating a protein-rich meal with some healthy fats, such as a breakfast smoothie with avocado or full-fat Greek yogurt with peanut butter. Avoid sugary foods that will spike your blood sugar levels. You should concentrate on eating a nutritious dinner with a balance of carbohydrates and protein after working out. The food should include protein pancakes, eggs on toast, or a balanced smoothie.

Guidelines For Fasted Cardio

To get started with fasted cardio, you first need to figure out whether or not it is a good fit for your lifestyle. Fasted cardio programs may benefit weight loss and fat burning, but fasting can also be difficult for some people. 

Whether you choose a fasted cardio routine at home or the gym, you must start slowly by easing into your routine and building up to more intense workouts over time.

  • Start slowly.
  • Hydrate before and during the workout.
  • Implement a moderate-intensity session.
  • Fuel up with a protein-rich meal afterward.
  • Stay away from high-intensity sessions.
  • Take some rest days.


Cardio on an empty stomach provides several health benefits, such as increased fat-burning and improved insulin sensitivity.Even though some studies suggest that exercising on an empty stomach is beneficial, this doesn't indicate that it always is. Exercising on an empty stomach could cause you to lose precious energy and reduce your stamina. In addition, you may experience other symptoms of low blood sugar, such as dizziness, nausea, or trembling.

There are different opinions on whether or not you should do fasted cardio daily. Some say that it is beneficial for weight loss and will help you get in shape more quickly, while others think that because it can be difficult for your body to burn fat when you're fasting, it's better to do a fasted workout once or twice a week.

Fasted cardio is essentially useless if you don't get enough sleep, eat only fast food, or focus on strength training. Ultimately, the decision is up to you. Do what works best for your schedule and needs!

Fasting safely and effectively flips the metabolic switch by using one fuel source instead of another. So, if you're looking for a way to get your metabolism going without turning to food or pills, consider incorporating fasted cardio into your routine. With this exercise regimen, you'll rely on fat as your energy source rather than glucose in your bloodstream. A brief fast can increase metabolism by up to 14%.

According to studies, there is no difference between fasted and fed cardio in body fat loss. So while it's unlikely that fasting cardio can increase your fat loss, that doesn't mean you have to eat before working out either. This decision ultimately comes down to personal preference and fitness objectives.

Walking without breakfast is known as "fasted walking" and has been shown to boost metabolism, accelerate fat burning, and maintain those effects throughout the day. Walking fasted is not considered true fasted cardio, but it does burn calories. Walking at a moderate pace for 30 minutes (burning 300-400 calories) will help you lose weight and reduce belly fat.

According to research, exercise after a fast increases muscle breakdown, which could result in a loss of strength. Therefore, eating something before doing cardio or weight training is important to maintain optimal energy levels and minimize muscle breakdown.

Key Takeaways

You can do fasted cardio at home in the morning, with or without equipment. It’s been proven by multiple studies that fasted cardio has many health benefits and can help you lose weight by burning fat more efficiently.

Fasted cardio is an exercise routine done early in the day on an empty stomach (nothing to eat for at least 12 hours). It is a nice way to start your day because it doesn’t disrupt your sleep cycle like getting up early would. Not only does it provide the opportunity to burn calories faster, but it also helps clear out any stored glucose in your muscles, which helps regulate blood sugar levels, so you feel fuller longer and have fewer cravings throughout the day.