Intermittent Fasting: The Why and The How
Intermittent Fasting was Google’s most-searched diet of 2019. And for legitimate reasons! Intermittent Fasting (also known as time-restricted eating) offers many health benefits that you just want to experience. In this article I explain why Intermittent Fasting is beneficial to your health and how to start with it when you have never tried it before. In addition, Antonie from Ketofit conducted research on the topic of fasting and performance and shares his thoughts. So if you are a sport minded individual and interested in trying this approach, just scroll down to that part!
First things first: why Intermittent Fasting?
Intermittent Fasting (IF) means you are cycling between periods of fasting and eating. Only looking at this term, it does not specify the recommended type of foods but only when you should be eating. Therefore, it is more often described as a certain eating pattern instead of a certain diet. There are different methods of applying Intermittent Fasting into your diet of which the most common ones are a daily 16-hour fast, a weekly 24-hour fast or fasting for 2 times a week by restricting your calories to 500-600 during these days.
Fasting has been practiced for a very long time, and not only for spiritual or religious reasons. Ancient hunter-gatherers did not always have the resources for food availability all year round. Therefore, humans evolved to function properly without eating food for extended periods. As a matter of fact, fasting so now and then is actually more natural than eating 6 times a day! Something that the food industry is lying about when telling you to eat multiple times a day to stay healthy and keep your metabolism high. Only to stimulate your snacking habits and cravings so you will buy more from their food products. Yes, that is unfortunately how it works nowadays.
So, know that you know the basics of intermittent fasting and its history (kinda, don’t want to get in too much detail on this part), let’s talk about the different health benefits of fasting!
Benefits of Intermittent Fasting
There are several health benefits to experience when you start with Intermittent Fasting. This free tool is a simple way to stay fit, to implement anywhere and to save time. It allows you to focus on things that truly matter without getting too caught up in counting macros and calories ;)
And what to think of the many health benefits intermittent fasting offers?
Improved mental clarity & focus
Lowered blood insulin & blood glucose levels and increased insulin sensitivity
Depletion of glycogen stores which makes it easier to get back into ketosis
Improved brain health
Increased energy levels
Cellulair repair: cells digest and remove old ones (also known as autophagy)
Lowered blood pressure
Increased human growth hormone (HGH)
Improved sports performances
Reduction of inflammation
In essence, fasting allows the body to use its stored fat for energy! In combination with exercising, this process will even go faster. The longer the fast, the more stored body fat you will burn.
A few extra notes to the first point since weight loss is the most common reason why people try intermittent fasting in the first place. The reason for this is that you eat fewer meals a day and therefore you reduce your caloric intake automatically. In addition, intermittent fasting changes your hormone levels in a positive way to facilitate weight loss. Lowered blood insulin levels and increased growth hormones levels, stimulate the release of the fat burning hormone called norepinephrine (noradrenaline). Because of the mentioned changes, fasting may increase your metabolic rate by 3.6-14%.
How to start with Intermittent Fasting
There are different types of intermittent Fasting as being said earlier, and the easiest way to start doing it is by skipping breakfast. If you have never tried fasting, take small steps! Instead of diving right in, try to eat your first meal of the day an hour later each day, until you have reached a 24 hour fast. In this way you give your body the time to adapt and you are less likely to experience feelings of hunger and cravings. Help yourself a bit, and make your first fasts as easy as possible. Then you really set yourself up for success!
It is really not as daunting or difficult as it may seem or sound. Once you have made it to a 24-hour fast, you can decide which protocol suits your lifestyle best. Ultimately, most people find the 16-hour daily fast to be the easiest, the most practical and the most sustainable. It is definitely the most popular amongst keto advocates, and it is my personal favourite as well.
What you can drink during your fast
Food is obviously not allowed during your fast yet drinking is. You can drink (lemon) water, black coffee, and tea (no flavoured ones) during your fast. Especially drinking enough salty water is highly recommended since you lose salt and water once you start fasting. Some research suggests you can also drink keto coffee during your fast, but it really depends per individual whether drinking this keeps you in ketosis or not. So if you don't measure your ketone levels closely, I would recommend to just stick to water, tea and black coffee. Better be safe than sorry!
Fasting and performance
Fasting and performance: for one individual it is seen a blessing, for the other more as a curse. This topic brings up a lot of questions and concerns amongst sport minded people, but what does the science say? Can fasting be beneficial to sport performances and results? And should you work out during your fast?
Fasting boosts human growth hormone
Several studies have shown that fasting might increase levels of human growth hormone (HGH). HGH is a hormone that plays an important role in the normal muscle development from children to adolescents. It also plays a huge part in the development of muscle. During this study a control group of healthy men where put on a two-day fast. During this period, a five-fold growth of HGH was measured. This means that fasting could be beneficial for muscle growth and recovery.
Maintaining a good shape
To optimize your performance, it is important to be in a good shape while you are training. Intermittent fasting is a great tool to stay in shape, even during your off-season. This method makes it possible for you to lose fat, and therefore stay lean. This process is mostly stimulated by lowered insulin levels and an increase in HGH. When you are in great shape, your performance is most likely to improve.
Another benefit of maintaining a lower body fat percentage is that you can proceed to gain lean muscle mass. With the traditional type of strength training and eating, most people will do a bulk (eating a high amount of calories) followed by a cut. During a cut, your body will be in a caloric deficit in order to lose fat. Unfortunately, chances are high that you will see a decline in performance and lose some hard gained muscle mass as well.
Should you workout during your fast?
This rather depends on your goal. If your goal is to burn fat or glycogen, then yes: fasting is a great way to improve this! Marathon runners and other endurance athletes can benefit greatly from running in a fasted state (also read this article about running a keto marathon). Emerging evidence shows that Intermittent Fasting might enhance the ability of aerobic exercise to increase endurance because the body switches to using fats and ketones as a source of fuel for muscles instead of carbohydrates. This makes sense, since fat oxidation increases when you fast. As a result, your body becomes better at metabolizing fat compared to relying on the carbohydrates that are readily available in a non-fasted state. Just make sure you perform a light, aerobic workout such as a long-distance run at average speed and that you refuel yourself afterwards. Sprinting is not a very good idea, since it requires glycogen as fuel.
When your goal is to optimize your performance and build muscle mass, then you are probably better off with consuming some good fats and protein before and after your workout. The extra fuel will push your performance and you will get the maximum out of your workout.
Fasted workouts work differently for everyone, there are people who swear by a fasted workout and feel like their performance and results are only improving. Dr Jason Fung, world’s most specialised doctor in Intermittent Fasting, is convinced that a fasted workout should not hurt your performance. “… our bodies have the wonderful ability to adapt to what’s available”. But with everything, there are also people who do not agree and really cannot stand to work out in a fasted state and feel dizzy, nauseous and weak. There is no right or wrong way here (expect for consuming your meal way too short before your workout ;)).
As you can read, there is a lot of upcoming evidence that (intermittent) fasting improves your body composition. Keep in mind though that this research is still in an early stage and information needs to be validated in higher quality human studies. But in combination with the muscle-sparing effect of ketosis, I would say you don’t have much to lose.
If you are a healthy individual, just give it a shot and try different eating windows, meals, and times to find your perfect way of fasting. The only way to find out to which group you belong, is to try it! That being said, it is a powerful tool, but not for everyone. Especially women are more sensitive and should be careful with the implementation especially when you have hormonal issues or when you are pregnant or breastfeeding.
About the author Antonie Bartels
Antonie Bartels has always had a passion for being healthy, building muscles and optimizing performance. As he has always oriented on new techniques to apply, he came across the ketogenic diet in the beginning of 2018. After a few months of reading and learning everything about it, he started with his own ketogenic journey. “The keto diet is so unknown in the Netherlands, yet so many people can benefit from it. Whether it is weight loss, optimizing performance, improving mental clarity or one of the many other benefits, a ketogenic diet should be out there to help them.” To share his knowledge and practices on a ketogenic diet, he founded KetoFit: a Dutch platform where you can find the all the information you need on the diet, combined with recipes to start your own ketogenic journey and a webshop where you can find keto supplements and products!
Antonie’s experiences with Intermittent Fasting
Recently I tried a 24 hour fast to see how this would influence my performance. Surprisingly it went way better than I expected! I had zero hunger and my performance was just as good as any other day. It was quite a demanding workout, but more focused on hypertrophy and more reps. For maximum effort and maximum strength I think I would go for a pre-workout meal to fuel the workout and also be a mental stimulus by knowing you have all the energy to kill it!