Intermittent Fasting: A Lifter's Guide

Intermittent Fasting: A Lifter's Guide

What is Intermittent Fasting?

In a perfect world, we could all train like beasts, eat like savages, and live shredded.

In the real world, diet and nutrition go hand in hand with the highest levels of performance. The best don't wing it and go to war; they have a plan of attack. And intermittent fasting, also called time-restricted feeding, is fast emerging as one of the most popular strategies in the game.   

In a single sentence: intermittent fasting is an eating pattern where you cycle between periods of eating and not eating. 

Unlike traditional nutrition strategies, it focuses less strictly on which foods to eat, but rather on when you should eat.

One of its major strengths is its simplicity: by reducing the need to study labels, tally macros and count calories, intermittent fasting offers a easy-to-follow, straightforward approach to nutrition.  

There are several different intermittent fasting styles, all of which split the 24 hours of a day or days of the week into eating periods and fasting periods.

These periods of eating and not-eating are commonly referred to as “windows”.

Intermittent fasting is easier than it seems. Without realizing it, most of us fast every day – because we don’t eat in our sleep, the average person is "accidentally" on an eating pattern of about 8 hours of fasting (due to sleep) and 16 hours of eating and snacking.

Intermittent fasting can be as simple as flipping those numbers around, so that you're going much longer without food – a 16/8 fast.

The 16/8 fast would allow you to only eat during an 8 hour feeding window.

If that sounds like too much starving, remember: you can eat as much as you want. But only in that single 8 hour period.

No food is allowed before or after (ie, during the remaining 16 hours of a 24 hour day).


Can you build muscle while intermittent fasting


If weight loss is the goal, that's really all there is to it.

If muscle maintenance or growth is your aim, we would add the caveat that intermittent fasters should boost protein intake to the optimal level for muscle-building.   

Here are examples of how a 16/8 fast would work:

  • You can do this by skipping breakfast, eating your first meal at noon and your last meal at 8 pm, for example.
  • Alternatively, you could eat from 9am to 5pm.

In either of the two examples above, you're fasting for 16 hours every day, and restricting eating to an 8-hour eating window. This is the most popular form of intermittent fasting, also known as the 16/8 method.

No food is allowed during the fasting period, but you can drink water, black coffee, tea and other non-caloric beverages.

Contrary to popular opinion, intermittent fasting is pretty easy to do, and its simplicity makes it convenient to stick with.

Compared to measuring out every calorie or googling the glycemic index of everything you eat, simply cramming your grub into an 8 hour window is refreshingly straightforward.

Hunger is usually not that big of an issue and becomes less problematic after the first week or so, as your body adapts to not eating for extended periods of time.

Surprisingly, many people report feeling better, thinking more clearly, and having more energy during a fast.

Taking supplements is generally allowed while fasting, if there are no calories in them.

*However, there are other considerations that could cause supplements to sabotage intermittent fasting. More on that in a bit.


What Science Says About Intermittent Fasting for Bodybuilding and Fitness

Why Intermittent Fasting Isn’t Just Another Fad Diet

Many scoff at intermittent fasting as merely a fad, or another “one trick cures all” diet approach. However, quality research with large groups of athletes has found intermittent fasting to be effective.

For many athletes its easier to stick with than other common eating strategies like Paleo, Keto, "Clean Eating", or If-It-Fits-Your Macros that have more complicated rules. While all these methods can work, there's an adage that remains true: the best diet is often the one you can stick with. For many, that's intermittent fasting.

But from a deeper, scientific perspective, there is another reason to consider giving intermittent fasting a try. Researchers were surprised to find it can provide a unique health-boosting benefit not seen with any of the other common nutrition strategies.

Fasting triggers a powerful physiological process known as autophagy.

As your cells constantly copy and replace themselves, occasional defects creep in – these are basically typos in the new cells’ DNA. And occasionally these defect cells are then copied and multiplied in the next round of cellular replacement, increasing aging, elevating risk of injury, and in some cases leading to the development of cancers.   

Autophagy (pronounced "aught-off-ah-jee") is a response unique to fasting, in which the body responds to a perceived lack of food by taking a cellular inventory and marking damaged or defective cells for destruction.  


Intermittent fasting triggers autophagy


In many ways, fasting allows your body to “clean house” and works like a systemic “reset” button. And the purpose of intermittent fasting is to push that button more frequently.

It plays a crucial role in maintaining muscle mass and neutralizing some of the degenerative aspects of aging. In fact, it’s the primary mechanism behind the anti-aging, potentially life-extending effects of calorie restriction.

Studies show that fasting can also reduce systemic inflammation, reduce oxidative damage, improve insulin sensitivity, and raise growth hormone levels.

If anyone is a little skeptical, it’s understandable. The online fitness community is famous for hyping things that science later deflates.

However, in the case of intermittent fasting and autophagy, it’s worth noting: the discovery of how autophagy works won the Nobel Prize in 2016.

It’s safe to say the benefits from autophagy are kind of a big deal. And they’re activated by intermittent fasting.


Supplements: Where Even Smart IF-ers Get Tripped Up

Intermittent fasting, especially initially, can make getting through your workouts brutal. There’s no way around it: it’s just plain tough to crush a workout on an extremely empty stomach. Pre-workout supplements can go a long way to providing an energy boost to help power through.

However, there’s a catch.


Flavored pre-workouts spike insulin - even if they contain no sugar or calories


In order for intermittent fasting to work, athletes must achieve and maintain unusually low levels of the eating-associated hormone insulin during their un-fed window.

If insulin rises, the physiology of the intermittent faster is no longer in a fully-fasted state, and the body does not begin the processes that make intermittent fasting effective (increased fat burning, autophagy, and others).

What every intermittent faster needs to know: Even if your pre-workout is sugar and calorie-free, it can still trigger a spike in insulin that will defeat the purpose of training on an empty stomach.  

New research into how insulin is released has conclusively demonstrated that the body does not wait for blood sugar to rise in response to digestion of calories and sugars, as previously thought.

Instead, the initial release of insulin is triggered by the brain, in response to signals it receives from taste buds on the tongue. This phenomenon is known as Cephalic Phase Insulin Release (CPIR).

Both animal and human studies confirm that tasting something sweet fools the brain into telling the body to release insulin – including zero calorie foods and sweeteners.

In fact, in one study researchers simply had participants swish and spit out a sweet zero-calorie beverage.

The effect on insulin?



Note that this doesn’t mean artificial sweeteners are necessarily horrible, or that diet sodas will make people pack on pounds of lard. Both still produce a much lower insulin response than their full-blown-sugar counterparts.  

What this does mean is that flavored pre-workout powders can raise insulin enough to reduce the effectiveness of intermittent fasting.

To get the real benefits of fasting and autophagy, insulin can’t spike pre-training (or outside the scheduled feed window). The well-documented CPIR effect of flavored pre-workout powders takes athletes out of a true, fasted state.   

For those who are on a ketogenic diet – the CPIR insulin spike from flavored pre-workout powders can sabotage your efforts as well.  

So what’s the best pre-workout to use with intermittent fasting or keto? We humbly offer a recommendation:


What's the best preworkout for intermittent fasting?


Untapped™ was designed to be a radically different, more effective breed of pre-workout. It incorporates the latest research on human performance, including emerging issues like CPIR.

Unlike traditional pre-workouts, Untapped fuels strength, endurance, and improvements in body composition without triggering any measurable insulin response.

It contains no sugars, carbs, artificial sweeteners, or calories, and does not trip the neurological circuit that activates the CPIR insulin spike.    


Intermittent Fasting: Summed Up

  • Intermittent fasting offers unique health benefits, in a simple-to-follow framework.

  • Virtually all the various feeding window protocols are great for athletes looking to lose weight and increase their general level of health.

  • During fasting hours, be wary of drinking anything sweet – even if it is sugar/calorie free. Stick to black coffee, water, or tea. A neurological reflex called CPIR kicks in when you taste something sweet. This reflex fools your body into releasing insulin and reacting as though you’ve broken your fast.

Also in News

The Truth About the Leg Press
The Truth About the Leg Press

Want to pack on slabs of muscle and take leg day to the next level? Turns out the ultimate leg day secret weapon has been hiding in plain sight. Here's everything you need to know... 

View full article →

What Builds More Muscle: Chicken or Beef?
What Builds More Muscle: Chicken or Beef?

It's a tale as old as bodybuilding itself: Which protein reigns supreme for muscle gains? The verdict is in, with the science to back it up. 🍗 vs 🥩 - Find out which takes the crown!

View full article →

Supercharge Your Back: The Trick to Proper Lat Training
Supercharge Your Back: The Trick to Proper Lat Training

95% of people hitting back make the same mistake, leaving gains on the table. Don't be one of them. Here's the play.

View full article →