Should You Work Out Fasted? | Sam Shoe Fitness

Should you work out on an empty stomach, or should you eat first? It's one of the most debated questions in fitness, especially for people trying to lose fat or improve performance.

Between fasted morning cardio and lifting weights after several meals, there are countless ways to structure your training.

So which approach is best? The better question is: Which approach is best for you?

In this article, I discuss some of the pros and cons to training while fasted as well as training later in the day after you’ve eaten.

Ultimately, the decision of which path to take will be up to you.

What Does It Mean to Work Out Fasted?

To work out fasted means to exercise before taking in any significant calories for the day.

Typically, water and coffee (without additives) are considered the only things that won’t cause you to break your fast after a night of sleeping.

This method of training became popular because many people believed that exercising on an empty stomach would cause the body to burn more fat for energy than if you had eaten beforehand. The idea behind fasted training is that after an overnight fast, insulin levels are lower, allowing your body to rely more on stored fat for fuel during lower-intensity exercise.

Some people associate this with ketosis, a metabolic state in which the body relies primarily on fat for energy because carbohydrate availability is very low. However, an overnight fast does not necessarily place most people into ketosis. While your body may burn a greater percentage of fat during a fasted workout, this does not automatically mean you will burn more body fat over the course of the day. The body will tend to burn less fat later in the day, to make up for the extra fat burned in the morning.

However, there may be other reasons why training fasted could be beneficial for you.

Does Your Type of Exercise Matter?

As a certified personal trainer and nutrition coach, I have found that training fasted has shown good results for clients based on the type of exercise they were doing.

For most people, I recommend eating before strength training. You want the energy and nutrients from a recent meal to be able to fuel you effectively for lifting weight. In my experience, most clients feel stronger after eating beforehand, particularly for resistance training.

However, I, personally, find it easier to do long forms of cardio on an empty stomach. Therefore, I like to run first thing in the morning before eating anything so that I am comfortable during my cardio. This will differ from individual to individual but I like to leave it open as an option because it works very well for me.

You also should take into consideration which time of day is most conducive for you to train. If you find it easier to wake up before work and strength train than you do after work, this becomes the best option.

The best option is always what you can do consistently day after day.

While fasted strength training may not be the most optimal way to grow muscle, if it is what keeps you going to the gym, I would recommend you stick to it. Long-term gains in the gym will come with consistency, no matter what time of day you train.

Pros and Cons of Fasted Training

The pros of training fasted may outweigh the cons for you as there are many quality reasons to train fasted depending on your preferences.

You will be getting your workout finished early in the day and you will be able to focus the rest of your day on other important things in your life.

There seems to be a consensus among my clients that working out early in the morning makes them feel better throughout the rest of the day. While I’m not an expert on the science of why that is, it may be something to consider.

As explained earlier, I feel better doing my cardio on an empty stomach than after having eaten. If you are staying under a high heart rate, your body will not need a lot of carbs in your system to perform steady state exercise. It will rely on mostly fat. This will still be present and available for cardio after sleeping all night, unlike readily available carbs.

On the flip side, because you do not have a ton of readily available carbohydrates in your body before eating for the first time in the day, you may not experience optimal performance in the gym for activities like lifting heavy weights and sprinting. Higher-intensity activities like heavy lifting and sprinting rely more heavily on carbohydrates for fuel. You will still be able to perform them, but maybe not as well as you would be able to after a few meals.

Another thing to watch out for if you decide to train fasted is compensatory eating. I have experienced clients that eat more throughout the day after training fasted because they experience a stronger hunger later in the day.

So, Should You Work Out Fasted?

As discussed, there are a few pros and cons to training fasted. Finding out what matters most to you should be your focus point.

Consistency and total daily nutrition matter far more than whether your stomach is empty. Keep getting in the gym, keep eating right, stay hydrated throughout the day and get good quality sleep.

These things are the building blocks for a healthy and progressing life in and out of the gym. If you are looking for something specific, measurable, and results-driven when it comes to your gym routine and fitness goals, I am happy to help. Check out my Free 7-Day Fat Loss Kickstart Guide and take a look at my different coaching options and get in touch!

Frequently Asked Questions

Is it better to work out fasted?

It depends on your goals and the type of exercise you are doing. Fasted training can be a good option for low to moderate intensity cardio if it feels comfortable for you. However, eating before strength training or high intensity exercise may help improve your performance and energy levels.

Does fasted cardio burn more fat?

During a fasted workout, your body may rely on a higher percentage of fat for fuel. However, current research suggests that this does not necessarily lead to greater fat loss over the course of the day or week. Total calorie intake, nutrition, and consistency are much more important factors for losing body fat.

Can you build muscle while training fasted?

Yes, you can build muscle while training fasted, especially if you consume enough calories and protein throughout the day. That said, many people find they have more energy and can lift heavier weights after eating.

Is it okay to drink coffee before a fasted workout?

Yes. Black coffee contains very few calories and is generally considered compatible with a fasted workout. Many people find that caffeine improves energy, focus, and exercise performance.

Should beginners work out fasted?

There is no rule that says beginners need to train fasted. If you are new to exercise, choose the routine that helps you feel your best and remain consistent. If you notice dizziness, low energy, or poor performance when training on an empty stomach, try eating a light meal or snack beforehand.

What should I eat after a fasted workout?

After a fasted workout, aim to eat a balanced meal that includes protein to support muscle recovery and carbohydrates to replenish energy stores. Foods such as eggs with toast, Greek yogurt with fruit, or chicken with rice and vegetables are all excellent choices.

Sam Shoe is a NASM Certified Personal Trainer and Nutrition Coach who helps busy adults lose weight and build sustainable habits through realistic fitness and nutrition coaching.