What is Intermittent Fasting?

What is Intermittent Fasting?

Intermittent fasting/Carb Cycling/Paleo – you may have heard of all of these but do you really know what they mean? Are these just new phrases coined by the fitness industry to confuse us and con us into buying the latest and greatest magazine/book/workout product?

Over the next few weeks, I’m going to fully investigate what each of these really mean, exactly what they are in simple terms and, most importantly find out if they really work!

Today’s post is going to be about Intermittent Fasting which includes Fasted Cardio.


In simple terms it’s a style of dieting which involves eating within restricted pre determined time windows.  The most common schedule is the 16/8, which means you cannot eat within 16 hours (this includes your sleep) but then you can eat all of your meals within the remaining 8 hours. An example of this would be:

Eating – 12pm to 8pm
Fasting – 8pm – 12pm.

There is also a 20/4 schedule which gives you only a 4 hour window for feeding. You do this for say 5 out of 7 days, the remaining 2 days you would eat as normal.  Some people do alternate day fasting, which is fasting for the whole day, then eating normal the following day and so on.


People claim that by doing this you accelerate your metabolism, live longer, ward off disease and basically make it easier than ever to lose fat and build muscle. These are big claims! So, does it actually work?

When your body is in a fasted state, it is no longer absorbing what it needs from your latest meal and so it goes to your energy stores instead, which is when the stored body fat can start to be broken down and converted into glucose. This all sounds great, but why doesn’t muscle loss occur and wont the metabolism be affected? Well research has shown that the body doesn’t actually think it’s starving until around 72 hours, at which the body will start breaking down proteins i.e. muscle.  So from this we can summise that fasting up to a 24 hour period shouldnt impact our metabolism or muscle mass.


  • Research has shown fasting can improve insulin sensitivity which helps reduce fat loss.
  • Exercising in a fasted state accelerates fat loss (we’ll talk more about this shortly).
  • Improves brain health
  • Reduces inflammation

This sounds like there are many benefits, however the research behind this has some flaws, small sample sizes and short time periods make the research less credible.


You may have heard of some of these methods, but if you want to give this a try then have a read through and see which one suits you best.


This is where you do your cardio whilst in a fasted state, so slightly more complex than just doing cardio on an empty stomach. Research has shown there are unique fat loss benefits as it increases lipolysis and fat oxidation rates, both of which lead to fat loss.

Example day:

In this example you are fasting for 16 hours.


Main rules:

  • Fast 16 hours per day. Water, tea, coffee permitted (no milk)
  • 8 hour daily feeding window
  • High Protein Diet
  • More carbs and calories on training days
  • Post workout meal = 50% of daily calories

If you want to give this a try, take a look here:



This is a 36 hour fast so is one of the more challenging fasting methods.


It works. However, so does exercising regularly, weight training and a high protein meal plan based on your measurements. It really depends on the person and their habits and how you deal with hunger control.

I personally have tried intermittent fasting for the past five days. I find it actually suits me as it fits easily into my schedule.  I usually like to go to the gym first thing before eating, so i’m able to easily manage the hunger pains. I also find it more convenient to prepare three large meals rather than 5 smaller meals.  I have found it reduces bloating significantly in the stomach area. The only drawback I have found is energy levels, but if you take BCAA’s 5-10 minutes before your workout this will give you a boost of energy.  BCAA’s are allowed as they’re calorie free and are known to retain muscle mass whilst on a calorie restricted diet.  It’s still too early to see any signficant fat loss but I will keep you posted!

If you like the idea of eating fewer larger meals then give this a go, just make sure you are still getting your overall macro nutrient splits correct as this will ensure no muscle loss. If you do try this, post here with your results!

Kellie xo


Leave a Reply

Your email address will not be published. Required fields are marked *