1. Replenish energy: After waking up in the morning, the body has consumed the energy reserves all night, and needs to replenish energy through breakfast to provide power for the new day's activities.

2. Improve metabolism: Breakfast can increase the calorie intake of the human body, thus increasing the speed of metabolism. Metabolism is the process by which the body consumes energy. Accelerating metabolism helps to lose weight and maintain a healthy weight.

3. Improve sports performance: When exercising in the morning, the body needs more energy to support muscle movement. Eating breakfast can provide enough energy for the body and improve sports performance and endurance.

4. Control hunger: skipping breakfast may lead to overeating at noon, thus consuming too many calories. Eating breakfast helps to control hunger and avoid overeating at lunch.

5. Maintain a good mental state: Eating breakfast can improve blood sugar levels and help maintain a stable mental state. Studies show that people who skip breakfast are more likely to feel anxious, irritable and inattentive.

6. Good for cardiovascular health: Eating breakfast can reduce the risk of cardiovascular disease. Studies have found that people who often skip breakfast have a higher risk of heart disease.

In short, eating breakfast is very important for fitness, it can provide energy, improve metabolism, improve sports performance, control hunger, maintain a good psychological state, and is beneficial to cardiovascular health. Therefore, in order to achieve the best fitness effect, we should form the habit of eating breakfast every day.