#3 Wall Pushup
A wall pushup is almost similar to a normal pushup except one uses the support of a wall to do the pushup. By using the wall to do the pushup, there is less stress us on the upper body and arms, and more focus on the back. You place your palms on the wall at shoulder width, with your body almost parallel to the wall and toes firmly placed on the floor. As one dips into a pushup towards the wall, it is the back which is at work and is being strengthened. One should do 20 repetitions of this exercise and 3 sets of the same.
#4 Plank to Pike Jumps
Plank to pike jumps is probably the most strenuous exercise because it tests your cardio while working out your entire body. Here you are in a plank position with your palms on the floor. Then in one jump you have to come to a pike position with your body almost vertical. After coming into a pike position, jump back into a plank position. This exercise is extremely hard to do, therefore one should try and do only 15 repetitions of these and then incrementally increase the number of repetitions. It works the back because your entire movement is premised on your posture and the support of your back. It is important to do this slowly and very deliberately to see any results.