Intermittent Fasting For Athletes | Dangerous or Good Idea?

The time is here! So many of you wanted Gronk Fitness to definitively answer this question and here it is. There has been a lot of buzz in the fitness community surrounding Intermittent Fasting (IF) and its fat loss and muscle gain benefits. Accounts of its results are everywhere, with testimonials from fitness professionals to movie stars. So, is it the perfect diet strategy for athletes…or is it dangerous and ill-advised?

What Is Intermittent Fasting? (I.F.)

For those of you who are not familiar with IF, there are several different variations, but all of them revolve around the premise of strictly eating inside certain eating windows and not eating anything at all during your fasting windows. Of course, water, no-calorie drinks and BCAA’s are allowed and usually recommended as well, as they will not affect the fasting window.

Technically, every one of us is already following a version of IF because we are not eating at night. So, unless you tend to sleepwalk to the fridge every night, you are fasting for about 8-10 hours daily and you don’t even know it.

The most common IF variation is the so called “8-16” model. That simply means that you consume all of your calories inside an 8-hour window and then you fast for the remaining 16 hours of the day. This is not very extreme, since many of us are already accidentally following it by sometimes skipping breakfast and not eating late at night, so it’s not too far from reality.

Deviating from the 8-16 model, there are other variations, such as the 6-18 and the 4-20 model which are a bit more extreme and there are certain variations that you don’t consume any food for 24, 36 or even 48 hours. The latter though, are more of a cleansing/detoxifying tool, used once every 6 months or so, rather than a part of viable diet plan.

So if an 8-10 hour fasting window is what’s natural and normal for the majority of us, why extend this window to 16 or 18 hours? Here’s the science behind it:

How Intermittent Fasting Works

The reality of the situation is that Intermittent Fasting has not been thoroughly studied and not definitively proven to work in any way, but the preliminary trials suggest that by cutting or eliminating calorie intake for a period of time (fasting) causes your body to dramatically deplete its glycogen stores. This in turn, directs the body towards using stored fat as its primary source of energy resulting in reduction of intramuscular fat stores and fat loss in general.

Ok, this is how IF promotes fat loss, but what about muscle and strength gain? With a reduction in fat on your muscle tissue, your muscle cells become more sensitive and responsive to insulin. Insulin is a powerful anabolic hormone that promotes protein synthesis, increasing muscle mass. This means that when you reach your eating window, your body’s ability to take in all of those important nutrients is significantly enhanced causing your muscles to grow.

Another common claim is that during a long period of not eating (fasting), Human Growth Hormone is considerably boosted, causing more protein synthesis and more fat loss.

So Intermittent Fasting seems like a powerful combination creating a snowball effect where your body loses fat causing it to become more sensitive to insulin, which helps you grow more muscle, which, in turn, increases metabolism, resulting in more fat loss and so on…

Intermittent Fasting Benefits

To summarize, the alleged claims of IF are:

  1. Improved Insulin Sensitivity
  2. Boosted HGH Production
  3. Enhanced Fat Loss & Muscle-Building
  4. Improved Oxidative Blood Markers
  5. Improved Brain Function & Focus
  6. Improved Overall Health & Prolonged Life Expectancy (less chance for chronic diseases like diabetes, cancer, heart disease etc..)

Intermittent Fasting & Muscle Loss

Before, we move on to the actual review of these claims, and we deliver our final verdict, let’s first examine a major concern most people have with IF, which is muscle breakdown during the fasting state. However, you should know that muscle loss does not occur that easily. It’s not like, if you don’t eat food for 16 hours, you’ve all of a sudden burnt through all your muscle mass. Your total amount of muscle is always the result of the equation {muscle synthesis minus muscle breakdown}. Both processes happen 24/7, and there is not much you can do to considerably influence them. Of course, major lifestyle changes such as prolonged eating on an extreme calorie deficit will likely increase the occurring muscle breakdown, whereas consistent weight lifting, will likely increase overall muscle synthesis, leading to more muscle mass.

So, no, IF will not cause any muscle loss because meal frequency is not nearly as important as overall caloric intake. If you look at the big picture, week after week, you are getting the same amount of calories and the same amount of protein, you are just changing the timing of nutrient delivery.

So, Intermitten Fasting is not a diet. It’s a DIET SCHEDULE.

If you are really worried about this however, you can just supplement some BCAAs during your fasting window, and that will pretty much eliminate any muscle loss risk.

Now, the problem with Intermittent Fasting is that if you look at all the research and studies, they all have a lot to do with CALORIC RESTRICTION. So, while the subjects are indeed on an IF eating plan, they are also on a caloric deficit which explains a lot.

Of course you are going to lose weight, if you eat less food. Nothing new here. In fact, this is why IF works so well. It restricts you from eating the majority of the time, so you won’t be able to eat as much as you normally would within the eating window. And of course, if you lose weight, your insulin sensitivity will likely improve, leading to more muscle gains. Nothing new here as well.

It’d be far more interesting to see a study where they compare a standard calorie-deficit diet with an IF calorie deficit diet, both on the same total calories. And of course there aren’t any because the results would be the exact same. Having said that, IF subjects might be more successful because, as stated before, it might be difficult to consume 2 or 3000 calories within a 4-6 hour window, which might induce more fat loss.

As for the improved blood markers and less oxidative stress IF can lead to, again, it’s all a matter of perspective. Eating less food overall, usually means eating less junk food as well, which will positively affect your health! Again…nothing new here! What about brain function though? We know that our brain’s only fuel is glucose which is essentially carbs. We need carbs to function, to think, to move. Being on a carb depraved state in the morning, will not improve your alertness or awareness. Instead it will more likely cause dizziness and loss of performance.

And lastly, HGH. The teeny, tiny increase of HGH you might experience will do simply nothing for your fat loss or muscle gain endeavors. Elite bodybuilders and athletes inject 2,3 or 4 times more HGH than their body naturally produces (plus a thousand more anabolic substances), in order to get results from the increased HGH levels, so why would you think that as a natural lifter, a 5-10% HGH boost will do anything for you?

The Real Problem With Intermittent Fasting

But in all fairness, all we proved so far is that IF may or may not work. If you are already using it and having success with it, who are we to argue? Keep doing what works for you and if this diet plan helps you stay on the right track, then it’s suitable for you. The main problem with IF is that it is not a LONG-TERM viable solution but rather a short-term fat loss tool.

Let’s be honest here. It’s not just about looking good and shredded. It’s not even just about becoming stronger and increasing your performance. We also want to improve our quality of life by ADOPTING a healthier lifestyle. So, getting ON a diet schedule such as IF, will eventually mean you’ll get OFF it, and that’s not what our advice is all about.

Final Words – Who Is Intermittent Fasting For & Does It Work?

So, who is Intermittent Fasting for and does it work? It’s not smart to believe that the actual fasted state equals more results. It is smart however, to consider IF as a short-term solution, especially if you are a bit overweight to start with and want to drop down to “regular” body fat percentages.

If you are currently trying it, and feeling great with it, by all means, carry on! It’s something that may or may not work and has virtually no disadvantages, so why not give it a try?

Train consistently, follow your meal plan, don’t force yourself to eat more or less and get those athletic results! There is no magic technique that you didn’t know about, to lose fat or gain muscle, just hard work and dedication. Scratch that….There IS a magic technique and it’s all about getting your mind right.


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