This is not a basic book of general calisthentics. There are no jumping jacks in the book. It is written by a former marine trainer. He has specialized body weight exercises for each group of muscles. The exercise range from easy to hard. He has a lot of advice on the benefits of bodyweight exercise over gym or home equipment. Some really good advice on motivation. I got it to help me with some exercises for restarting a fitness program. I liked that there are a bunch on multistep exercises which will help with mobility, balance, and flexibility. I mainly read to get a list of exercises. I did not read in full the last sections which are workout programs that use his exercises for full body workouts. The workouts vary over time, and while I won't use his specific workouts, I plan to try some of the exercises in the bodyweight portion of my fitness routine (which does not exist at the current time, but the variety of exercises may work into my expected future program. Everyone will probably find a new exercise amount the 100 or so in this book.