Fasting Exercise Is Not For Everyone

Fasting Exercise is Not For Everyone

When active exercise and proper dieting have become the code of conduct for many bodybuilders, fasting exercise has become an exercise mode that includes both active exercise and proper dieting.

Most people think that exercising after a period of fasting can accelerate fat burning. This is because the glycogen stores in the body are about to be depleted after a long fast, which means that the body can consume more fat during exercise. However, the fat-burning effect of fasting exercise may not be superior and fasting exercise also brings great uncertainty for different groups of people.

Fasting exercise can burn fat, but not necessarily for everyone. Especially for those who train at home during the epidemic, fasting exercise needs to be considered.

Different Types of Fasts

Whether training at home or going to the gym, fasting training is starting to gain popularity. So, there are many different types of fasting methods:

■ 16:8: No eating for 16 hours, and an eight-hour eating window.

■ 5:2: Five days of normal eating, two days of fasting.

■ No food afternoon: fasting after lunch continues until the next morning.

■ One meal a day: eat only one meal a day.

■ Fasting every other day: eat normally one day and fast the next.

Fasting Exercise Is Not For Everyone

The Practical Significance of Fasting Exercise

Effective fat burning

Exercise on an empty stomach, especially for fitness people whose main need is to lose fat.

When you start exercising when you are hungry, the amount of glycogen available in the body is very low, so more fat is burned and used in this situation.

A study published in the British Journal of Nutrition in 2016 also confirmed this view. Compared with subjects who exercised after eating, fasted exercisers were able to induce a significantly higher proportion of fat oxidation.

Improve adaptability

Fasting exercise can purposefully enhance the body’s own ability to adapt. From a long-term perspective, the body can slowly adapt to hunger, which is of course helpful for people who lose weight.

Treatment method

Both traditional and modern medical systems recommend appropriate fasting as a therapeutic intervention for the management of some chronic non-infectious diseases. Combining fasting with exercise training can optimize hormone levels and increase insulin peaks.

Drawbacks of Fasted Exercise


The problem of hypoglycemia caused by fasting exercise will also reduce exercise performance significantly. For example, you can run five kilometers aerobically on an empty stomach but can run eight to ten kilometers after eating. Although the percentage of fat burned on an empty stomach is higher, the total calorie burn is higher with exercise after eating.

Adverse reactions

For muscle gainers who do fasting exercise for a long time, the number of repetitions of maximum strength may be reduced, and the speed of the recovery phase after exercise will also be slower than that of exercisers who eat normally, while those with low blood sugar are prone to dizziness and even dizziness after exercising on an empty stomach. Bodybuilders with short-term shock problems, insufficient sleep, and a poor mental state may also experience hormonal imbalances.

Inability to perform strenuous exercise

Fasting exercise is limited to some low-intensity aerobic exercises, such as jogging and aerobic yoga. Because the body is not able to perform an excessively high-intensity exercise in a fasting state. For example, in high-intensity intermittent exercise HIIT, if you train in a hungry state, you often feel powerless or briefly dizzy. This is usually due to hypoglycemia caused by fasting, and the effect of exercise will also be directly affected at this time.

Suppresses the afterburn effect

Afterburn effect: this means that oxygen uptake is maintained at a high level for some time after exercise, to restore the hyperactive muscles to a resting state by breaking down stored fat and carbohydrates.

The greater the exercise intensity, the stronger the “afterburning effect.” “Intensity” here does not refer to the “length” of the exercise time but to how “tired” it is when exercising.

Since fasting exercise is usually performed with lower-intensity aerobic exercise, compared with high-intensity aerobic exercises such as circuit training and anaerobic resistance, the number of “afterburning effects” will also be reduced to a certain extent.

Fasting Training May Not Be For Everyone

Muscle gainer

For those who build muscle, the disadvantages of fasting training outweigh the advantages.

In an eight-week randomized controlled trial of fasting exercise, it was found that muscle gainers who ate intermittently gained less muscle mass and increased dimensionality more slowly than those who ate normally.

Because glycogen is the preferred fuel source for strength training, fat becomes the main feed when training on an empty stomach and reduces training and exercise times.

In other words, fasting exercise has an impact on muscular endurance, maximum strength, and maximum strength repetitions. It can even affect muscle regeneration and functional recovery after exercise.

Fat loser

For fat losers who believe that fasting exercise is beneficial, they will choose to perform super-intensive exercise on an empty stomach, which may lead to a rapid drop in blood sugar levels.

For example, 30 minutes of aerobic running and four hours of hiking have an enormous difference in body calorie consumption. Fasting all the time can lead to insulin deficiency problems.

Office workers, long-term stay-up people

For people with poor mental state and lack of sleep, but still insist on fasting exercise, such as 996 office workers, people who stay up late for a long time. Hormone metabolism in the body can be difficult to meditate on, and even hormonal imbalances can occur.

Therefore, a moderate amount of fasting exercise can effectively burn part of the excess fat in the body. But more importantly, striking a fluctuating balance between burning fat and maintaining energy stores in the body.

Occasional fasting exercise can effectively stimulate the body to actively burn fat. On the other hand, exercising on an empty stomach is not a good option for people who already have health conditions.

Fasting Before Exercise Also Needs to Choose the Right Time

Although many studies support the advantages and disadvantages of fasting exercise, whether to choose fasting exercise is a personal choice.

Fasting exercise requires an adaptation process

For some people who have adapted to doing yoga on an empty stomach for half an hour in the morning, forcibly changing the habit of eating breakfast first will not have a beneficial effect on the body’s metabolism.

But fasting exercise must be a gradual adaptation and gradual process. Suddenly choose to fast for 12 hours and exercise. The metabolic crisis brought to the body is unprecedented.

You can choose to gradually reduce your carbohydrate intake before exercise, but still maintain a proper protein intake, or as an alternative to fasting exercise.

It is also possible to roughly divide those who are adaptable to fasting exercise and those who are not adaptable. For those who are just starting, their exercise performance in the fasting state is likely to be greatly affected.

And people who already have a certain exercise foundation need to lose stubborn fat since their body has adapted to a certain fixed aerobic pattern for a long time. Doing a fast-paced workout will help them burn fat effectively.

You should be taking your body composition seriously

Visbody has made measuring body composition more accurate and more accessible than ever, which is the 1st 3D Body Scanner that applies both Instant Body Scan and Bioelectrical Impedance Analysis technologies together.

Testing your body composition offers you a glimpse of what your existing body weight is made up of. After all, it’s not about a number on a scale. It’s more important to learn how much of your body weight is made up of fat, water, bones, and muscle.

To help you get motivated (or stay motivated), here are five reasons you should be taking your body composition seriously!

1) You reduce your chances of suffering from high cholesterol and the side effects that come with it.
2) You reduce your chances of developing heart disease, diabetes, or stroke.
3) You’ll be able to recognize pre-diabetes early.
4) You reduce your chance of premature death
5) You’ll likely improve your body composition & physical fitness

Other considerations

If you want to exercise on an empty stomach, it is best to choose low-intensity aerobic exercise to avoid high-intensity aerobic exercise or dizziness when there is no oxygen.

When training on an empty stomach, pay attention to always maintaining water and electrolyte intake to avoid fluid loss. For example, coconut water, which is popular with bodybuilders, considers the advantage of being rich in essential electrolytes and low in calories and sugar.