Does running in the morning help you lose weight?

There is a widespread belief that running on an empty stomach in the morning can burn more fat.

There are two reasons:

  • Reason 1: after a night of sleep rest, the body’s glycogen has been depleted, this time up early to run, the body can only directly call on fat to provide energy, so greatly conducive to fat consumption; Weight loss, of course, is even better.
  • Reason 2: wake up in the morning after the lowest metabolic rate, after exercise can significantly improve the metabolic rate, metabolic rate can maintain the best state throughout the day, increase energy consumption, and therefore help to reduce fat.

These two reasons seem to make sense? Is that what it is?

Can you burn out your glycogen after a night’s sleep?

Generally speaking, the average person has about 5 grams of blood sugar in the blood, liver contains 100 grams of liver glycogen, muscle contains 400 grams of muscle glycogen, the human body by the three parts of sugar, they can provide heat for exercise.

When the human body is in a quiet state, each kilogram of body weight consumed 1 kilocalorie of calories per hour, and the energy consumption level in deep sleep is actually lower than this standard.

Even when sleeping energy consumption is 1 kcal / kg / h, an adult male, if the weight of 60 kg, 8 hours of sleep at night, the energy consumption is 1 × 60 × 8, 480 kcal.

Assuming that the 480 calories are all powered by glycogen decomposition, and that one gram of sugar breaks down to produce four calories, then:

The maximum amount of sugar consumed in a night’s sleep is 120 grams.

In other words, after a night’s sleep, the body is still the remaining sugar = 480-120=360 grams.

You see that? A night’s rest doesn’t cause glycogen depletion.

It’s not true that running in the morning burns more fat. 

After a night’s sleep, the body consumes up to a quarter of its sugar. There is no scientific basis for saying that “after a night’s rest, the body’s glycogen has been depleted.” 

This also assumes that during sleep, the ideal value is calculated entirely from the energy provided by sugar decomposition. In fact, the 480 calories consumed during sleep cannot all be provided by sugar. About 50% of sugar and 50% of fat are consumed by sugar. In other words, a night’s sleep actually consumes only about 60 grams of sugar. 

So saying, “because sleep consumes all the sugar in one night, running in the morning depends entirely on fat to provide calories” is a myth. 

Running in the morning will still be a mixture of sugar and fat, and there is not enough scientific evidence to suggest that running in the morning is better for burning fat. 

Moreover, blood sugar is a very important physiological indicators, can not fluctuate at will, the normal blood sugar concentration of 80 to 120 mg / dl, too low blood sugar will lead to hypoglycemia, hyperglycemia is diabetes. 

We remember that during the physical examination, the hospital has to stress that fasting blood sugar is checked, because only then can the blood sugar level reflect whether the body’s glucose metabolism is normal or not. If it is really after a night’s sleep, the body’s glycogen is exhausted. Isn’t it true that hypoglycemia occurs in the morning? 

In fact, this is very unlikely. 

First, the body does not consume glycogen after a night’s sleep, second, the body will mobilize all possible factors to keep blood sugar stable. 

So the idea that “after a night of sleep, the body’s glycogen has been depleted” may seem plausible, but it doesn’t stand up to scrutiny. 

Feeling hungry after getting up in the morning is by no means equal to having no sugar in your body.

Low metabolic rate in the morning, need to accelerate metabolism through morning running?

Sleep at night is indeed the slowest time for metabolism. All we need to do at this time is to maintain our breathing, heartbeat and basic metabolic activities. During the day, we engage in various activities of production and life, and metabolism is enhanced. Metabolism is, of course, significantly enhanced during exercise, so this is true.

Exercise can not only enable the human body to maintain a high metabolic state, faster and more efficient burning of fat, and after exercise, this high metabolic state will still be maintained for a period of time, which is called excess post exercise oxygen consumption.

Excess oxygen consumption after exercise means that your heart rate may have returned to a quiet level for some time after exercise, but you are still breathing faster, that is, maintaining a high metabolic state.

You may not be aware of it, but the fact that you breathe a little faster than you did before long after exercise is definitely what fat people dream of every day-to lose weight while sitting.

Because breathing faster for a long time after exercise means faster caloric decomposition.

Of course, morning running will accelerate metabolism, does not mean that morning running can lose weight, any time running, can accelerate metabolism, not because the movement time changes, and make a big difference in metabolism.

Therefore, it is correct to speed up metabolism in morning running, but there is no scientific basis to say that only running in the morning accelerates metabolism.

Morning running advice

While running on an empty stomach in the morning does not result in any more fat loss than running at other times, running in the morning still has a number of benefits, such as a good habit of going to bed and getting up early, and a good habit of eating breakfast every day.

Here are some suggestions for morning running:

  • It is not necessary to eat before running in the morning, but it is recommended to drink some water in the morning before running. After a night’s sleep, the body will evaporate some of the water in a non-sweaty way. The body may be mildly dehydrated. It is perfectly normal to replenish water. If you feel hungry, you can eat a little, but don’t eat too much.
  • The morning outdoor temperature is relatively low, pay attention to keep warm, add a coat is a good choice.
  • If you’re in the middle of winter, wait for haze to disperse and then run. This is because haze in the morning is very bad for your health.


Running on an empty stomach in the morning definitely reduces fat, but no more than exercise at other times. 

Don’t eat too much food when you run in the morning, or it may cause stomach problems. 

I suggest you wear a mask and a thin coat for your morning run.

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