What component of body composition can increase with resistance training?

The component of body composition that can increase with resistance training is lean body mass. Resistance training, which includes exercises that exert force against resistance, stimulates muscle fibers to grow and strengthen. This process, known as hypertrophy, leads to an increase in muscle mass, which is categorized as lean body mass. Lean body mass includes not only skeletal muscle but also organs, bones, and water content within the body.

While metabolic rate can also improve with resistance training due to increased muscle mass enhancing calorie expenditure at rest, the primary focus here is on the direct influence of resistance training on body composition. In contrast, resistance training is generally aimed at reducing body fat rather than increasing it. Water weight can fluctuate based on various factors such as hydration status, but it is not a sustainable increase associated specifically with resistance training. Thus, the most direct and relevant effect of resistance training on body composition is the increase in lean body mass.