Bioelectrical impedance analysis (BIA) is a method used to estimate body composition, particularly the amount of fat and muscle in a person. It works by sending a small electrical current through the body and measuring how easily the current flows. Since fat and muscle conduct electricity differently, the results can help determine a person's overall health and fitness levels. This technique is often used in gyms, clinics, and research settings because it is quick and non-invasive. Devices like handheld monitors or scales equipped with BIA technology can provide instant feedback, making it a popular choice for those looking to track their fitness goals or manage their weight.