Strong arms can be achieved by using body weight exercises in lieu of weights according to bodybuilding.com. Body weight exercises can be easily adapted to all fitness levels and require little or no equipment.
Some classic examples of arm-strengthening body weight exercises include triceps dips, push-ups and pull ups. Simply change position to make a particular movement more challenging, or add repetitions to the set to increase the intensity of body weight exercises. Get more out of body weight exercises by doing each movement slowly and concentrating on the movement, making sure that the muscles are flexed and fully engaged during the exercise.