"The book features three four-week programs, with over 90 exercises, all illustrated with step-by-step photographs, making them easy to master. Here's how it works: 4 minutes of high-energy aerobic training to raise the heart rate and metabolism ; 3 minutes of resistance training to strengthen muscles and bones ; 2 minutes of core-strengthening exercises for the abs and back ; 1 minute of stretching and deep breathing, a vital component of a well-rounded program" -- page [4] of cover.