Alternating Single Arm Medicine Ball Push Ups is another body weight exercise that can be done before starting your weight training regimen. Mind you, it is a bit more difficult and more advance than doing regular push up. You also need a real Medicine Ball for this exercise.
This exercise can also be combined, once you start your weight training regimen by adding them at the beginning, in the middle or at the end of a good chest day. Or doing whole body workouts or circuits for the people who are trying to lose weight.