How much muscle mass do you loose per day when on bed rest?

During prolonged bed rest, individuals can lose approximately 1-2% of their muscle mass per day, particularly in the lower body. This muscle atrophy occurs due to a lack of mechanical loading and physical activity. The rate of muscle loss may vary based on factors such as age, baseline fitness level, and overall health. Thus, even short periods of inactivity can lead to significant muscle loss over time.