You've certainly heard or seen workout gurus or influencers describe intermittent fasting and how they've been able to adopt this dietary pattern into their everyday routine on the internet or social media.
Is it, however, safe to fast while exercising? If so, should you exercise while fasting or after eating. Hopefully, we can give you enough information in this post to help you make the right decision for you!
Overview of Intermittent Fasting
Let us begin by defining intermittent fasting. Intermittent fasting is when a person adds short periods of fasting into their daily routine. Intermittent fasting can take many forms, including alternate day fasting, one or more days a week fasting, 16/8 (fasting for 16 hours and eating for the remaining 8 hours), one meal a day (OMAD), and others.
This diet plan has grown in popularity due to its potential to help people lose body fat while also improving their overall health.
Intermittent Fasting and Exercise
You're probably thinking if incorporating an exercise regimen into your daily routine while practicing intermittent fasting is a healthy thing to do. Yes, the answer is yes! Fasting sometimes while exercising is healthful and safe, and it can help you achieve some of your physical goals faster.
Normal physical activity offers numerous health benefits, including helping to build/maintain muscle mass, accelerating fat loss, lowering your risk of different diseases, and improving your overall mood and mental health.
Unfortunately, there haven't been many studies that combine exercise and intermittent fasting. However, based on the few studies that have been conducted, it appears that when exercise and intermittent fasting are combined, people can expect to lose more body fat and show greater signs of improvement in overall health when compared to a more normal eating pattern in which people eat for 12+ hours per day.
The intermittent fasting participants in these research were also able to maintain their muscle mass and daily calorie expenditure. It's also worth noting that these research ensured that their subjects maintained their calorie intake while fasting intermittently.
Other research have looked into exercise and intermittent fasting, but their participants cut back on calories while fasting. These trials did not show the same benefits in indices of overall health or a greater reduction in body fat.
Based on these findings, you may wish to maintain your calorie intake while intermittent fasting in order to achieve your physical and health goals.
Fasted vs Fed Workout
The second significant concern is whether you should exercise while fasting. The simple answer is that you should exercise in a method that makes you feel good and that you can continue to do for the rest of your life. The most crucial aspect of exercising is that you continue to do it.
But let's go a little deeper.
There are two types of exercise: endurance (often known as cardio) and resistance training. These two types of exercise involve different metabolic pathways and may result in different physical effects if performed while fasting.
Unfortunately, there hasn't been a lot of study done on intermittent fasting and different sorts of training, but we'll try our best to highlight what we do know.
Training for Endurance
Endurance training is often defined as any sort of physical activity that raises and maintains your heart rate for an extended length of time. Running, biking, swimming, and even strolling are some examples.
People often engage in this type of exercise because they enjoy it and because it is an excellent way to burn calories and lose body fat.
What are some of the advantages and disadvantages of conducting endurance exercises while fasting?
Pros
A benefit of fasted cardio is that you may be able to burn more fat than you would if you exercised when fed. In fact, a study of 405 papers revealed that not only is fasting cardio better at burning fat, but it also helps lower blood glucose and insulin levels.
Fasted exercise may help you shed weight faster while also improving other elements of your overall health.
Cons
Before engaging in fasting cardio for an extended period of time, use caution. Have you ever heard of a sportsperson "hitting the wall"? When you exercise cardio, your body uses some fat and some glycogen (stored glucose) for energy. When you run out of glycogen, your body becomes extremely exhausted and you have very little energy.
This is more common in highly skilled athletes who engage in very severe activity for an extended amount of time, such as jogging for more than an hour, without eating before and/or during their workout. You'll be alright if you plan on performing 30 minutes of fasted cardio. Stop exercising if you feel unusually weary or dizzy at any moment. To be safe, eat before or snack on something halfway through if you plan on performing more than an hour of heavy cardio.
Another disadvantage is that you may become more hungry during your workout. This may cause you to end your workout quicker than expected. Remember that the most important aspect of exercise is the ability to maintain it.
Resistance Exercise
Resistance training is commonly used to describe any sort of weight-bearing exercise or weight lifting. People will participate in resistance training because they enjoy it and it is an excellent approach to improving muscle and strength.
What are the benefits and drawbacks of fasted resistance training?
Pros
Unfortunately, there hasn't been a lot of research done on fasted resistance training. However, one study discovered that subjects who exercised while fasting burned more fat during their workouts than those who trained after eating (9). This indicates that conducting resistance exercise while fasting may help you shed more fat than doing it after eating a meal.
Cons
Fasted resistance training has the disadvantage of making muscle building more difficult. Eating upregulates particular pathways that aid in muscle growth and development, therefore not eating before working out may inadvertently inhibit the full capacity of these pathways.
Fasting, on the other hand, promotes growth hormones, which aid in muscle building and maintenance. Unfortunately, it is not feasible to say which of these two effects is stronger or if fasted resistance exercise is beneficial or detrimental to muscle building at this time.
Fasted resistance activity, like endurance training, may lead you to feel hungrier, causing you to finish working out earlier than planned.
Summary
Intermittent fasting combined with exercise is an excellent strategy to achieve your physical and health goals.
You can certainly alter when you exercise in relation to when you eat to speed up your progress, but the most important thing is to listen to your body and do what feels best for you.
Find a routine that makes you happy and make it a habit that you can follow for the rest of your life!