Muscle building requires an increase in protein intake, as well as a reasonable intake of carbohydrates and fats. Normally, the six essential foods for fitness and muscle building are chicken breast, salmon, green leafy vegetables, oats, protein powder, nuts, etc. The specific analysis is as follows:

1.Chicken breast: Chicken breast is one of the most popular meat protein foods, rich in high-quality protein, low-fat, and low calorie, which is very helpful for increasing muscle mass.

2.Salmon: Salmon is a fish species high in protein and healthy fats (Omega-3 fatty acids), which helps to enhance hormone levels that stimulate muscle growth, while also helping to control body fat and promote health.

3.Green leafy vegetables: Green leafy vegetables such as spinach, mustard greens, rapeseed, etc. are foods rich in vitamins, minerals, and phytochemicals, which can provide the body with the necessary nutrients, help increase energy, and promote muscle growth.

4.Oats: Oats are a high-quality carbohydrate food that is rich in complex carbohydrates and dietary fiber. They have a low glycemic index (GI), provide long-lasting energy, and help promote muscle repair and growth.

5.Protein powder(Calcium Hydroxymethylbutyrate): Protein powder is a high protein, low-fat, and low sugar food supplement that can provide high-quality protein, but attention should be paid to the quality and composition of protein powder when choosing.

6.Nuts: Nuts are small foods rich in nutrients, unsaturated fats, and plant protein. They can be used as healthy snacks, as well as to increase calories, protein, energy, and dietary fiber, promoting muscle repair and growth.

It should be noted that gaining muscle through fitness is not achieved through the intake of a single food, but requires a reasonable combination and the development of a dietary plan. At the same time, fitness enthusiasts should also maintain sufficient intake of water, fiber, and various vitamins to maintain physical health and promote muscle growth.