Fasted cardio involves working out on an empty stomach, typically first thing in the morning. Some experts and fitness enthusiasts claim that this allows you to burn more fat and calories than working out after you've eaten. Currently, there is not enough scientific evidence to support these claims.
Although working out on an empty stomach may cause your body to burn more fat in the short term, that doesn't mean you'll lose body fat in the long term. Exercising without eating may interfere with your exercise goals and make losing fat challenging.
Lifting on an empty stomach doesn't make you ``lose'' muscle, but you aren't maximising your muscle gain and hard work.
Benefit #1: YOUR BODY USES FAT FOR FUEL. When you don't eat before a workout, your body does not need to go through the glycogen storage before using fat for energy. Thus a big reason for why this is a great way to burn fat during your workouts. Benefit #2: WORKING OUT WITHOUT FEELING FULL OR BLOATED.
It is a common belief that training on an empty stomach will help you burn more fat. However, there is no scientific evidence to support this claim. In fact, working out on an empty stomach may actually be counterproductive to your weight-loss goals.
Overall, the experts agree: Exercising in the morning is the best time of day to work out for logistical, effective and health reasons. When it comes to weight loss, a 2023 study published in the journal Obesity found exercising between 7 a.m. and 9 a.m. could help.
“There is insufficient data proving that fasted training leads to better fat loss over time, which is one of its common claims.” Some data shows that longer-duration workouts benefit from fed training, but shorter-duration workout performance can be similar whether fed or fasted, experts say.
In general, for healthy individuals looking to lose weight or get fitter – morning workouts are perfectly fine. In most cases, they are even a great choice (see next section).
Exercising between 7 a.m. and 9 a.m. has been associated with having a lower waist circumference and body mass index than people who work out during midday or evening, according to a study published Tuesday in the journal Obesity.
"A person who is attempting to lose weight by not eating may lose weight in muscle first before fat," he says. How does that happen? Well, the body likes to go for carbs (glucose) for energy first.
That plan is called the 30-30-30 rule. It's a simple but catchy idea that encourages you to eat 30 grams of protein within 30 minutes of waking up and then get 30 minutes of low-intensity exercise. The 30-30-30 rule now has millions of followers on TikTok.
However, exercising on an empty stomach will also cause you to lose lean muscle mass at the same time, which can hinder long-term weight loss. Exercising without eating first can cause dramatic shifts in your blood sugar, and when it drops quickly you can feel nauseous, light-headed or dizzy.
Despite its popularity, fasted cardio has not been proven to help burn more calories or fat. But some people may prefer the approach for a variety of reasons. For example, if exercising in the morning before breakfast works better for your schedule and doesn't cause discomfort, you might make a habit of it.
Unfortunately, even if you do 100 crunches a day, you won't lose the fat from your belly. Not a chance. And since a toned belly is exactly what everyone is looking for, the market is saturated with all kinds of belly-busting contraptions and workout DVDs.
When working out in the morning, you use your energy from fat reserves as your carb reserves are almost used up, which helps reduce fat and aid in weight loss, especially when exercising on an empty stomach and using fasted cardio. In fact, this can burn up to 20 percent more body fat, Gardner states.
I have heard that exercising on an empty stomach burns more fat and at a faster rate. Is this true? Research using healthy young men has shown that doing aerobic exercise when fasting increases the use of stored fat as an energy supply. The reaction may be related to the low insulin levels that occur during fasting.
Muscle breakdown.
This means your body can just as easily break down your muscle stores and tissue, liberating stored glucose to use as fuel in your fasted cardio sessions. That means, not only are you not burning your body's fat stores, you're actually breaking down your own muscle as well.
For women, the results show that eating before they exercise is better than eating after if they want to burn fat. Women's bodies tend to burn fat more easily than men's, and are not fuelled so much by carbohydrates. Moreover, women are much better at conserving carbohydrates during exercise.
If you don't eat, you might feel slow-moving or lightheaded when you exercise. If you plan to exercise within an hour after breakfast, eat a light meal. Or have a sports drink. Focus on carbohydrates for the most energy.
Aerobic exercise includes any activity that raises your heart rate such as walking, dancing, running or swimming. This can also include doing housework, gardening and playing with your children. Other types of exercise such as strength training, Pilates and yoga can also help you lose belly fat.