The #1 Time of Day to Exercise for Fat Loss

Your goal is fat loss.

So, you roll out of bed in the morning and have some carbs before the gym so you can give your all in your workout.

You do this because you’ve heard for years that having more performance will give you greater fat loss, right?

Well….

This is where we need to get more nuanced.

The discussion between fasted training versus fed training for fat loss is a difficult one to have because there are some severe egos and tribal attitudes involved.

Many times, people don’t like to abandon what they “know” in exchange for new data or input.

So, let’s debunk some of this and talk about what’s happening at a cellular level so you can burn the most fat without wasting time.

The Data

A study from the British Journal of Nutrition examined twenty-seven different studies regarding fasted training versus fed training to determine the differences regarding cellular metabolism.

They found that the fasted training groups had significantly more fatty acid oxidation.

Fatty acid oxidation means the fat enters the mitochondria and oxidizes as fuel.

This process is not to be confused with lipolysis.

Lipolysis is the liberation of triglycerides and fatty acids into the bloodstream to get broken down.

For example:

When you drink a cup of coffee, it increases lipolysis. So, the saying is, “Coffee increases fat loss.”

Hold your horses.

Coffee increases fat mobilization but will return to the cells if you don’t burn it.

Lipolysis can mobilize fat. Oxidation is the actual burning of fat.

So, the British Journal of Nutrition found that fasted training provided much more fat oxidation.

It's kind of a no-brainer, right?

Here’s the problem, though.

The Energy Paradox

If you’re training and weaker from fasting, what good is oxidizing more fat?

So, if you go to the gym and you’re lethargic and low on energy, you won’t be able to oxidize the fat.

Sure, maybe you’ll do some lifts and get something of a pump on, but it’s nowhere near the level of performance you’re used to.

If you’re lucky, you might burn 200 calories.

Then, Bob walks in charged, fueled up, ready to crush it because he ate carbs before the workout.

He’s throwing weight around, slamming his workout, and burning like…1000 calories! Who cares if his fat burn percentage is slightly less, right? His absolute calories were more!

And, at the end of the day, calories in versus calories out trumps all based on the research.

It can seem that way, but hang on….

There’s more data.

The Power Athlete Study

This study blew my mind.

The study demonstrates that, when looking at power athletes, there was no difference in performance between a fasted state and a fed state.

There was no difference when it came down to their power or capacity.

What mattered the most was eating enough the days prior.

They did a similar study on people during Ramadan who trained fed versus their fasting window. 

Still, no difference in performance. Fascinating.

The biggest factor was whether they fueled enough the days beforehand. Their fluid levels and sleep matter, too.

Fluid levels are determined based on what was eaten. You consume about 3 to 4 grams of water per carb.

So, if you ate 300 grams of carbs yesterday and are adequately hydrated, you will have better fluid balance than the person who did not.

You will have more intracellular water, which will serve as leverage for you to lift more.

That concept matters much more than putting fuel in before your workout.

The Fat Loss Verdict

Take two people.

One trains fasted, and one trains fed.

If we can assume performance is the same between fasted and fed training, and they both burn 500 calories during their workout, the fasted person will have higher fat oxidation and burn more fat.

Yes, we could get even more nuanced, saying the person who’s fed will have a higher thermogenic rate and higher nonexercise activity thermogenesis.

Yes, that will squeak out a few more calories and is an adequate consideration.

However, when it comes down to fat loss, resistance training, or power training, the studies point to more fat loss while in a fasted state.

When you’re fasting, you’ll have more AMP-activated protein kinase phosphorylation.

This process means you’re getting deeper into a caloric deficit because you’re already in a deficit from fasting.

Don’t shoot the messenger.

The BMM Takeaway

The results are in.

According to science thus far, training while fasting is the best time to train for fat loss.

Normally, this means first thing in the morning for most people.

But it comes down to your personal schedule.

If you work graveyard shifts and sleep during the day, hitting the gym in the evening would technically be your morning. So, it makes sense to go before you’ve had food.

The actual time on the clock is irrelevant.

What matters is training on an empty stomach.

Keep in mind that if you’re used to training with food first, it may be a bit of an adjustment for you initially.

Go easy in those first few workouts until your body adapts.

Once it does adopt your new schedule, you’ll work out with full confidence, knowing you’re oxidizing fat for fuel.