If you don't want to hassle with a gym or weights, you can still do some basic push up variations to build your arm strength. Building the muscles in your arms will not only help you look more fit, but you will also find that daily tasks (such as picking up your kids) and your cardio exercise will become easier. Here are some variations of the traditional push up to get you started:

The backwards dip is like a reverse push up. Start by sitting in a "crab-walk" position. Make sure your feet and hands are facing forward and that your arms are straight. Lower yourself to the ground by slowly bending your arms. Then push yourself back up so that your arms are straight. This push up variation primarily strengthens your deltoids, shoulders and biceps. Start with 2 to 3 sets of 20.

The cobra push up combines the cobra yoga pose with a push up. Start by getting into a "downward dog" yoga position (which is a V-shape with both your hands and feet touching the floor). Slide with your shoulders first into a cobra position. Your arms and legs should be straight with your back slightly arched. Now return to the downward dog position. Repeat this 5 to 8 times.

Start this push up as if you were doing a traditional push up. Bring your arms in so that your hands are touching. Make sure that your hands are directly under your chest and lower yourself to the ground, as you would for a traditional push up. These push ups work your chest and forearms. If you are not used to working these muscle groups, start with just a few repetitions, focusing on your form. Start with 5 to 8 repetitions and work your way up.