The Definitive Guide to Fasted Weight Training

If You want to know how fasted weight training can help you burn fat and gain lean muscle, you'll want to read this.

Do you ever feel your stomach growling before you even get out of bed?

Most of us here have experienced the feeling.

We’re active people, which means many of us feel hungry all the time.

Chances are if you’ve ever heard of intermittent fasting, you think it sounds terrible.

“Not eat? For a set period? WHY?”

When you look at the research, though, you’ll see that fasted weight training can accelerate fat burn and promote lean muscle development. Who doesn’t want that?

Now, this article isn’t about intermittent fasting as a lifestyle or diet.

This article is specifically about fasted weight training benefits and how you can get the most out of fasted training.

So if you want to burn stubborn fat and reap some of the more elusive weight training benefits, then you’ll want to read on.

Let’s dive in.

What Is Fasting? (and What It's Not)

When you eat food, your body breaks it down into small molecules, and those molecules enter your blood.

Your body then releases insulin to transport nutrients for use or storage.

While your body is digesting food, you’re in a “fed” state. This can last 3-6 hours depending on your meal.

Once your body finishes processing the food, your insulin levels then drop to baseline levels. This is known as the “fasted” state.

Even if you are a bit hungry or you feel like your stomach is empty, you might not be in a fasted state.

For example, if you eat a large lunch around noon and then start getting hungry around 4 or 5 pm, that doesn’t mean you’re in a fasted state.

But if you have your last evening snack around 7 or 8 pm and then get up around 5 am to workout—you’re in a fasted state.

In the world of intermittent fasting, “Fasting” doesn’t refer to not eating for days. Instead, it refers to the practice of abstaining from meals for a set period. You might eat from 3 pm to 10 pm, for example, and stick to drinking water and tea during your non-eating hours.

In recent years, intermittent fasting has become popular among people like Tim Ferriss and Terry Crews.

The Benefits of Fasted Weight Training

Why would someone want to start their workout in a fasted state?

The answer, it turns out, is simple:

When your insulin levels are low (you’re in a fasted state), then your body uses body fat stores as the primary source of energy.

When you combine this with fasted weight training, then you can achieve some truly awesome benefits, including the following:

1. Burn More Fat Faster

Studies show that fasted exercise increases lipolysis and fat oxidation rates, allowing you to burn fat faster.

When you exercise, your body needs energy to perform. Naturally, it goes for glucose (from food, primarily carbohydrates) since it’s easier to convert to energy. When you’re in a fasted state, though, and glucose is unavailable, your body begins to convert fat into energy.

Research from Northumbria University found people can burn up to 20% more body fat by exercising in the morning on an empty stomach, rather than exercising after breakfast.

2. Increased Blood Flow to Your Abdominal Region

Studies show that fasted training increases blood flow to your abdominal region.

So what?

Well, the lower abdominal area is usually one of the most challenging areas to lose fat…and blood flow is one of the reasons for making it so difficult.

By increasing blood flow to your abdominal region, you’ll be able to burn more belly fat faster.

No, this isn’t targeted fat loss. Fasted exercise just helps your body naturally burn more fat from stubborn areas.

3. Increase Muscle Growth

Studies show fasted weight training results in greater anabolic response to a post-workout meal when compared to fed training.

This means fasted training can help your body respond better to post-workout nutrition and begin building and restoring muscle quicker.

This equals gains!

Another study found fasting increased growth hormones by 2,000% in men and 1,300% in women! Growth hormones work to protect lean muscle mass and restore metabolic balance.

4. Improve Peak Power and VO2 Max

Studies show that fasted training can improve peak power and VO2 max.

Translating that into weightlifting benefits, fasted weight training could help improve lifting output over the duration of a workout.

VO2 max is vital to endurance athletes, but it also has a place in the gym. In short, VO2 is essentially your body’s ability to use oxygen.

Regarding weight training, studies show that those who have a higher VO2 max burn more fat from exercise.

So it makes sense that fasted training can help you burn more fat by increasing your VO2 max.

5. Improved Insulin Sensitivity

The typical Western diet has most people consuming more calories than the body needs. Even those who are weight training (bulking) often eat more calories than needed to grow muscle.

After doing this for an extended period, the body becomes more resistant to insulin (the hormone responsible for delivering nutrients where they need to go).

Is there a solution to this problem? Yes!

Regular fasted training causes your body to release insulin less often, making your body adapt and become more sensitive to the limited amounts of insulin.

This increase in insulin sensitivity makes it easier for your body to convert energy, burn fat, and increase blood flow.

How to Properly Do Fasted Weight Lifting

Ready to incorporate fasted weight training into your routine? Here’s a simple guide to get you started:

  1. Start Fasted Weight Training in the Morning. If you train in the morning, this makes it super easy. Simply wake up and train before you eat breakfast. If You Chose Evening Workouts, Eat Dinner Afterwards. If you typically train in the evenings, eat dinner after your workout. This will also help your body absorb the nutrients from the meal and improve your anabolic response.
  2. Take BCAAs Before Exercising: We’ll get into more details in just a bit—but your body breaks muscle down while your exercising in the gym. BCAAs (primarily, Leucine) have been shown to suppress muscle breakdown, making it easier for you to burn fat and not muscle during your fasted workouts. Take 3-5 grams of BCAAs before your fasted workout to maximize lean muscle growth.
  3. Be Patient: Your body has to adapt to training in a fasted state. The benefits aren’t all instantaneous. That said, research shows that your body adapts to training in a fasted state and learns to use energy more efficiently. So in the first couple weeks, you might notice a slight decrease in lifting volume, but that’ll go away quickly. Stay at it.

Are There Negative Side Effects of Fasted Training?

Now, all is not perfect in the world of fasted weight training.

There are downsides and potential negative side effects of training while fasted.

First, science aside, weightlifting when hungry sucks! Doing anything while starving sucks! Just being plain hungry sucks.

That said, after a couple of weeks of fasted training, you’ll likely find you’re not hungry in the mornings anymore. If you do wake up ravenous, though, don’t deprive your body of what it needs. Eat something!

Now onto more logical side effects of fasted training.

  1. Initially, You’re Going to Feel Weaker: If your body is used to burning carbs for energy, then you’re going to feel a bit weaker doing fasted training—at first, at least. Once your body adapts, it’ll learn to use fuel more efficiently and will be better able to burn fat stores for energy. So don’t try a fasted workout for your next big weightlifting competition or anything. It’s something you’ll need to adapt too.
  2. Fasted Training Can Increase Muscle Breakdown Rates: Research shows that fasted training can increase muscle breakdown rates, making it harder for your body to repair and grow stronger—but there’s a caveat. Research also shows an increased post-workout anabolic response from fasting training, meaning your body will better absorb nutrients and heal faster. So do the two effects negate each other? Possibly. Plus, you can almost completely suppress muscle breakdown rates caused by fasted training by supplementing with BCAAs before your workout.

And some people just don’t like fasted training. If that’s you—don’t worry about it! This is not a one-size-fits-all approach, and you can get similar results through great nutrition and a well-rounded exercise plan.

The Bottom Line on Fasted Weight Training

If you’re looking to burn fat and build muscle, fasted weight training can be just the thing to help you do it.

If you’re considering fasted training, now is a great time to give it a try.

It can make a huge impact on your workouts, lifestyle, and overall fitness and physique.

TFT Team

Our team at The Fitness Tribe often collaborates together to produce content. When you see “TFT Team” this is because the content was not written by a single author, but rather a team effort.