Intermittent Fasting and Bodybuilding

Date Posted... 28th Feb 2020


Intermittent fasting is known to be one of the more popular diets within the fitness industry right now and there are many health benefits that come with it other than reducing weight. We’re going to take a look at the different types of intermittent fasting and how this could affect your fitness routine when you’re going through your bulking and cutting phases.
Intermittent fasting has been used mainly for the benefits of losing weight but can come in beneficial to a bodybuilder’s routine. As there are so many ways to follow an intermittent fasting routine, there will probably be some trial and error as you try to find the sweet spot for your body and lifestyle.
Let’s dive in.
What Is Intermittent Fasting?

Intermittent fasting is a term used to describe various meal timing schedules that switch between voluntary fasting and non-fasting over a period. So, it doesn’t specify what you eat, but when you eat instead.

Some people who struggle when it comes to maintaining a good healthy diet 24/7 might be interested in intermittent fasting due to its freedom to allow more choice in what you’re eating as long as it’s within your feeding window (the time in which you’re eating). This is of course to a certain extent; it doesn’t mean every meal you do have can be a dominoes.

Intermittent fasting is often seen less as a diet and more of a lifestyle, which is why many people seem to find this easier to maintain than a standard calorie restricted diet.

Different Methods of Intermittent Fasting

There are many different ways to work an intermittent fasting diet into your lifestyle, as are there so many different methods for you to try to see what is right for you. Below are the 4 most popular methods of intermittent fasting you will see around today.

The 16:8 Method

This method consists of eating within an 8-hour window of your day and then fasting for the other 16-hours. For example, you’d skip breakfast and eat between 12:00 PM and 8:00 PM, or have an early dinner and have your eating window between 10:00 AM and 6:00 PM. This would be considered one of the easier methods as it’s technically only the one meal you’d need to miss, and you’ll be sleeping through 8 hours of your 16-hour fast.

The 5:2 Method

This method means you eat normally for 5 days of the week and restrict calories to 500-600 on two non-consecutive days of the week. So, for example you may choose to restrict calories every Tuesday and Thursday and consume your normal calorie amount on the remaining days of the week. Being able to choose your fasting days means it can be adjusted around your lifestyle, allowing it to be much easier to maintain.

Eat – Stop – Eat

This method means maintaining a fast for a 24-hr period. Two days in your week will consist of a 24-hr fast, for example after your last evening meal at 7:00PM, your next meal wouldn’t be until 7:00PM the NEXT DAY. But you could do it from breakfast to breakfast or lunch to lunch, whatever you find works best for your routine. The hardest thing with this is a lot of people will find it difficult to get to the end of that 24-hr fast without snacking on anything, I know I’d struggle big time.

Alternate Day Fasting (ADF)

It’s exactly how it sounds, ADF means fasting every other day. There are a few different ways to execute this as some people would do a full 24-hr fast every other day and others might just restrict their calories to 500-600 on their fasting days. Again, this will be more difficult than the first two methods we talked about, but a lot of people would work up to these more intense methods after understanding more about how these types of diets work for them personally.

Eating/Drinking During Your Fasting Period vs Eating/Drinking During Your Feeding Period

The only thing that you should be consuming during your fasting periods are liquids that contain 0 calories. Water, tea or coffee (without milk, cream or sugar) and any non-calorific drinks.

The number one question to do with fasting seems to be ‘Can I drink a diet soda, or will this break my fast?’ Technically a diet soda fits right into the above category as it has no sugars, carbs or calories. But the artificial sweeteners in those drinks can cause sugar cravings which isn’t going to make this fasting process any easier at all, especially if you’re struggling to stick with it anyway.

When finishing your fasting period studies have shown eating a high-carb meal will be the most beneficial. The activity of the genes that increase calorie consumption and fat burning is further increased with the high-carb meal compared to a low-carb meal [1].

One thing to always keep in mind during these diets, is although they allow more food options this doesn’t mean you can eat unhealthy, fatty meals. Following a healthy balanced diet during your feeding periods is going to maximise the benefits you’re going to see from following an intermittent fasting cycle.

Key Benefits For Bodybuilding & Competition

There are many benefits of an intermittent fasting lifestyle that aren’t just about losing weight and looking good. The diet will cause changes in your body which will be a positive for your fitness routine, especially for bodybuilder and fitness competitors.


The first and most obvious is fat loss. Cutting fat is an integral part of a fitness competitors routine, because this is what gives us that high definition, ripped, vascular look we strive for. Eating less meals is automatically going to reduce your calorie intake which is proven to be an effective way to reduce fat.


One study shows that HGH (Human Growth Hormone) is greatly increased after 5/day fast. the 24-h pulsatile pattern of GH secretion was examined and found that after a 5/day fast the pulse frequency, concentration and amplitude was greatly increased. This is going to help when it comes to gaining muscle during your intermittent fasting diet [2].


Insulin is also affected when partaking in an intermittent fasting diet. Studies have shown that insulin sensitivity improves, and levels of insulin drop too. This again is another plus as lower insulin levels allow stored fat to be easier shed [3].


Intermittent Fasting has also been known to cause a cellular process called autophagy [4]. In simple terms it means the stress your body feels from essentially ‘starving’ itself signals your cells to create membranes that look for the dead, diseased, or worn-out cells and use these for energy. Think of it as your body cell recycling systems which has great health benefits!


One thing we worry about when it comes to cutting is how much muscle mass you might lose during this process. It has been shown that intermittent fasting is more effective than standard calories restriction diets in retaining more of your muscle mass [5]. We’re always going to lose some lean mass, but it’s never going to harm anyone to do as much as they can to keep as much of it as they can!


There are many other benefits Intermittent fasting is known to have like, inflammation, heart health, brain health and anti-aging… But research on intermittent fasting is very much in early stages and we should wait for more conclusive evidence to give a reliable answer.


Majority of studies done have been to examine the weight loss benefits of this type of diet, so it’s difficult to say exactly that it’s going to be a good diet to try whilst trying to build muscle.

Technically due to the reduction of calories and just your lack of macronutrients in general this means you’re not going to have enough protein and in turn won’t be able to build new muscle tissue effectively. You’re also probably going to have to do some workouts fasted and this can reduce performance and ultimately results. Plus, you might find it hard to get all your calories in in such short eating windows.

Due to all these reasons it might not be the best diet to follow when trying to build muscle. But that doesn’t mean to say you don’t start using intermittent fasting during your cuts?

To try it OR not to try it?

So, there you have it! We’ve gone through different methods of intermittent fasting, the key benefits for people in the competition world and the negative too. But ultimately, I think it comes down to…

Do you think you PERSONALLY would be able to control this kind of diet and periods of no-eating?

If yes, give it a go! Start with the 16:8 and move into the tougher methods as you begin to understand the process a bit more. There isn’t any harm in seeing how it works for you. You never know, you could get into the best shape of your life!