The above video goes through all the exercises mentioned in the ebook except for the pull up - which are excellent if you have the strength. Exercises include the bodyweight squat (legs), push ups (arms, shoulders, back, core), lunges (legs) and sit ups (stomach/abdominals).

Lunges work your glutes in your hips and butt along with the hamstrings and quadriceps in your thighs. The calf muscles in your lower legs, your abdominal muscles and your back muscles act as stabilisers during this exercise. Vary these each week but keep the same technique for 3 sets. Do as many as you can each time with a short break in between. 

Main muscles worked by the plank are the abdominals; rectus abdominis) and the transversus abdominis. These are the muscles in your belly, and the muscles that sit in between your belly and your side muscles. Stabilising muscles contracted include the obliques in your waist, your hip flexors, your quadriceps in your thighs, the pectoralis major in your chest, and a group of muscles covering your ribcage called serratus anterior, or “boxer’s muscle.”

Hold the plank for a minute without sinking your lower back to avoid injury. You can mix them up by raising your legs either one at a time or alternately. If you want to go nuts, raise your arms out in front as well. You'll be dripping in no time.

Sit ups work all your abdominal muscles when you vary the actions from week to week. The important thing to remember with sit ups is not to strain your neck or back. There's no need for anyone to hold your feet down and the most effective sit ups are done slowly and up to about 45 degrees. Do as many as you can comfortably and aim for 3 sets. Never lose form so don't push it.

Note: Don't be thinking that doing countless sit-ups will reveal your abs! They will indeed build your abs, but the only way to reveal them is to burn fat around your belly - for which training the largest muscle groups is most effective, combined with steady-paced cardio and high intensity interval training. It's more fun to work the abs/core in exercises like the bear crawl or plank hold.

Push ups are a great compound exercise. They work all the muscles in your back, shoulders, triceps and to some extent your biceps. Do 3 sets, each time doing as many as you can to failure. This will vary a lot according to the individual. You can mix them up between hands shoulder width apart, wide handed and diamond.