In this video, Dr. Ekberg explains the differences between walking and running for weight loss. He explains that the body primarily burns fat for fuel during aerobic exercise, such as walking at a leisurely pace. In this state, the body uses oxygen to efficiently convert fat into energy. However, when exercise becomes more intense and oxygen supply is limited, the body starts to rely on glucose from glycogen stores, which is less efficient and triggers the release of cortisol and insulin. This can lead to cravings and muscle breakdown. Therefore, for maximum weight loss, walking is the better option for overweight individuals looking to reduce insulin resistance.
Key Insights:
- Weight loss is not simply about burning calories, but rather about understanding how the body uses energy.
- The body primarily uses two methods to produce energy: oxidative phosphorylation (with oxygen) and glycolysis (without oxygen).
- Aerobic exercise (like walking) allows the body to use oxidative phosphorylation and preferentially burn fat for fuel.
- Anaerobic exercise (like running) relies on glycolysis and burns more glucose/carbohydrates than fat.
- Aerobic exercise, particularly when fat-adapted, allows for sustained fat burning and can be done for longer periods of time.
- Running and intense exercise can trigger cortisol and insulin production, which can lead to cravings and carb dependence.
- Walking is generally better for weight loss, especially for those who are overweight or insulin resistant.
- Reducing insulin resistance is key to long-term weight loss and overall health.
Transcript
Every year, millions of people resolve to lose weight. However, many of them end up gaining the weight back. Is this because they’re doing something wrong or lacking in character and willpower? Many people believe in the idea of „no pain, no gain“ and that suffering is necessary to achieve results. But is that really true for weight loss and fat burning, or is it just cultural conditioning? In this video, we will uncover the truth about how weight loss really works so that you can achieve your goals once and for all.
When it comes to weight loss through exercise, the common belief is that we need to expend more energy to burn fat. This theory is based on the idea that if we use up more energy or calories than we consume, our body will burn fat as a source of energy. While this theory makes sense, the reality is not as simple.
To understand the difference between walking and running for weight loss, we need to look at how our body generates energy. One way is through oxidative phosphorylation, where energy is produced in the presence of oxygen. In this process, our body uses fat or glucose as fuel, and with enough oxygen available, it efficiently produces energy in the form of ATP. Fat adaptation occurs when our body becomes efficient at using fat as its main source of fuel.
During rest and low-intensity exercise, our body prefers to use fat for energy, with about 85% coming from fat and 15% from glucose. Both fat and glucose are channeled into the mitochondria, where oxygen is used to produce ATP. This is the preferred and most efficient way for our body to generate energy.
The alternative way of generating energy is through glycolysis, which occurs when there is a lack of oxygen or insufficient oxygen supply. Glycolysis is an inefficient process that occurs in the cytoplasm of the cell. It can only produce two units of ATP from one unit of glucose, compared to the 38 units of ATP produced through oxidative phosphorylation. This emergency mechanism is important for situations where oxygen is limited, such as during sprints or emergencies.
Now, let’s explore how walking and running affect fat burning. Walking at a moderate intensity, usually below 120 beats per minute heart rate, allows for sufficient oxygen supply to the mitochondria. This means that our body can continue using oxidative phosphorylation as the main way to generate energy. As a result, we primarily burn fat for fuel, especially if we are fat-adapted. Fat adaptation occurs when our body becomes efficient at using fat as its main source of fuel.
As the intensity increases and we start huffing and puffing, oxygen supply becomes insufficient for the mitochondria to sustain oxidative phosphorylation alone. At this point, our body starts relying more on glycolysis and burning glucose for energy. The more intense the exercise, the more dominant the use of glucose becomes. Although some fat is still burned during high-intensity exercise, most of the fuel comes from glucose.
Many people believe that more calories burned during exercise lead to more fat burned. However, the truth is that you can only burn fat up to the aerobic threshold, beyond which glycolysis and glucose burning become dominant. In other words, you can’t burn more fat than your body can provide oxygen for.
It’s important to consider the effects of different exercise intensities on our body and overall weight loss. Walking at a moderate intensity, such as aerobic exercise, primarily relies on fat burning. This leads to stable insulin levels and a reduced tendency to store fat. In contrast, high-intensity exercise, like running, triggers cortisol and insulin release, increasing the body’s carb dependence and fat storage.
Moreover, running typically requires higher caloric expenditure per unit of time than walking. However, it’s important to note that running cannot be sustained for as long as walking. Therefore, the total calorie expenditure may not be significantly higher. Additionally, running increases hunger and cravings, often leading to overeating. This can offset any extra calories burned during the exercise.
When it comes to choosing between walking and running for maximum weight loss, walking is the clear winner, especially for those who are overweight or insulin resistant. Walking allows for a longer duration of exercise without triggering excessive cortisol and insulin release. This helps in maintaining fat adaptation and a steady fat-burning state.
However, this does not mean that running is completely excluded. If you are fit, insulin sensitive, enjoy running, and seek some variety in your exercise routine, running can still be incorporated. Regular aerobic exercise is essential for overall health, reducing insulin resistance, and promoting fat loss.
In conclusion, the focus should be on reducing insulin resistance for sustainable weight loss. Walking, particularly for those who are overweight or insulin resistant, is the preferred exercise for fat burning. By understanding how different exercise intensities affect our body and insulin levels, we can make informed decisions about our exercise routines. Remember, the goal is to reduce insulin resistance and improve overall health, rather than just burning calories.
