Fasted vs. Fed Workouts: See the Benefits and Downsides

fasted vs. fed workouts

Great! You’re motivated to work out, you have your new outfit and playlist ready to go, now, the question is when? Should you train in the morning or afternoon? Shoot for a fasted vs. fed workout: which one is better? As is often the situation, this is going to be another case of “it depends.”

What is Fasted Training?

First, you may be curious what is meant by a “fasted workout.” The premise behind fasted training is that after a long fast (for example, when you wake up in the morning and haven’t eaten for many hours), your body is already in fat-burning mode. Whereas it can normally take your body 20 – 30 minutes to use the stored glycogen (energy) in your bloodstream before tapping into fat stores, training in a fasted state could allow you to use fat for fuel from the get-go.

What is Fed Training?

So, if a fasted workout means training on an empty stomach, then logically, a “fed workout” will be the opposite. Yes, it does mean working out after a meal, but the timing and type of meal you consume pre-workout can make a big difference in how your body functions. Typically, your body will be in a “fed” state for four to five hours after a meal. That gives you a window of opportunity to have a great workout.

Fasted Workouts Pros and Cons

There are both pros and cons to doing your exercise in a fasted state:

Benefits of Fasted Workouts

1. Knock it out first thing—if you’re training fasted, it’s probably going to be in the morning soon after waking up. This means you get it done before anything else can get in the way or sidetrack you. And if you’re checking off that exercise box first thing in the morning, you’re setting up the rest of your day for positivity and productivity.

2. Burn body fat exclusively—this may be the most popular reason to do your exercise on an empty stomach. You don’t need to power through those first 20 – 30 minutes of stored carbohydrates/glucose to reach the fat-burning zone. You’re already there with your very first step.

3. You’ll burn more belly fat—yes, while it’s true that you’ll burn fat from all over your body, because of the “receptors” in your fat cells (alpha and beta receptors) in combination with chemicals that help burn fat called catecholamines, the exercise you’re doing helps increase circulation to those “stubborn fat” areas so you can theoretically burn it more easily.

Downsides of Fasted Workouts

1. Stress hormones are doubled—when you fast, your body is under stress and releases the stress hormone cortisol. In similar fashion, when you exercise, your body perceives this as a stressful activity, also causing it to release cortisol. If you exclusively train in this combination of states, over time, it can stunt your fat-burning and muscle-growth potential.

2. You may hit bottom and run out of energy—there’s a reason why workouts are powered by food… to give you the energy to sustain all the activity you’re doing. When training on an empty stomach, you’re prone to running out of energy if your workout is tough or runs long. That can translate to sub-par workouts with less intensity and progress.

3. You limit the times you can work out—if you can only train when you’re in a fasted state, that means you might only be able to train first thing in the morning or you might have to have excessively long periods of time between meals to get to that fasted state.

Fed Workouts Pros and Cons

There are also pros and cons to doing your workout in a fed state:

Benefits of Fed Workouts

1. Get great high-energy workouts—having healthy carbs before you hit the gym allows your muscles to tap into the energy needed to power through tough workouts. This helps you go harder at the gym for longer.

2. Keep that hard-earned muscle mass—when you exercise in a fed state, your body doesn’t have to tap into resources like muscle tissue to get fuel. In the scheme of things, keeping your muscles intact and adding more muscle with intense resistance training will help boost and maintain your metabolism, thus allowing for greater overall fat and calorie burn.

Downsides of Fed Workouts

1. You may suffer from indigestion—training fed isn’t for everyone. Some folks just feel better training on an empty stomach. Some people may feel too full or sluggish after eating or not assimilate their food quickly, leaving them feeling bloated and lethargic. If this is the case for you, you may want to focus on better meal timing, different food choices, or fasted workouts.

2. You won’t be burning fat immediately—if your main goal is to lose body fat, then blunting that fat burning by eating before a workout is not ideal. Your body will have to work through all the energy it gleans from the food that is broken down into glucose in your bloodstream before it ever taps into your fat stores.

Fasted vs. Fed Workouts: Which is Better?

Of course, the working out fasted versus working out fed question has been studied many times over, and you might think working out while fasted will help you burn more fat. While this is true in the purest sense (you burn more fat while you’re exercising in a fasted state), studies show that overall fat loss is the same with fasted vs. fed workouts.

The bottom line is that you should do your workouts when they fit your schedule and preferences. Since most adults don’t even meet the bare minimum of suggested physical activity per day, just getting your workout done is going to reap rewards, no matter if it is a fasted vs. fed workout.