How to build muscles?

Resistance training: Muscle growth is stimulated by resistance training, which involves using weights or other forms of resistance to overload the muscles. Resistance training creates microscopic tears in the muscle fibers, which triggers the muscle to repair and grow stronger.
Progressive overload: To continue building muscle, you need to progressively increase the resistance or weight you use during your workouts. This is known as progressive overload, and it ensures that your muscles are constantly challenged and forced to adapt.
Muscle damage: The muscle damage caused by resistance training is a key stimulus for muscle growth. This is why exercises that create more muscle damage, such as eccentric (lowering) contractions, are often more effective for building muscle than exercises that create less damage.
Metabolic stress: Another factor that contributes to muscle growth is metabolic stress, which occurs when the muscles are under tension for an extended period of time. This creates an accumulation of metabolites in the muscles, such as lactate, which can stimulate muscle growth.
Hormones: Hormones such as testosterone, growth hormone, and insulin-like growth factor (IGF-1) also play a role in muscle building. These hormones are released in response to resistance training and help to promote muscle growth and recovery.
Nutrition: Adequate nutrition is essential for muscle growth. Consuming sufficient amounts of protein, carbohydrates, and healthy fats can help to provide the energy and building blocks necessary for muscle repair and growth.
Rest and recovery: Muscle growth occurs during periods of rest and recovery, not during the workout itself. It is important to allow the muscles time to recover between workouts and to get enough sleep to support muscle growth.