High-level health and wellness are within the reach of most persons choosing physically active lifestyles. The body contains more than 600 muscles, which respond to the degree of use or disuse given them in exercise and daily life activities. If not challenged, muscles will start to shrink in size and strength. In contrast, when progressively overloaded, muscles will respond with increases in strength and endurance to effectively function in physical activities every day. A well-rounded fitness program will include resistance training exercises to increase musculoskeletal fitness and overall health. An understanding and appreciation of musculoskeletal fitness involves a discussion of its association with several health-related diseases including osteoporosis, cardiovascular disease, hypertension, diabetes, and obesity.