Workout without weights seems strange to some people but there are some fantastic exercises that are really effective.

Building muscle without weights can be achieved by doing push ups, squats, lunges, dips, back extensions and calf raises.

Running is really effective. If there is nowhere to run, you can jump rope or any other type of aerobic exercise.

When doing a workout without weights you may feel a little awkward doing some of the exercises (having your partner sitting on your back while you do squats) but performing any exercise is better than none. As with any training there are always simple exercises that require no equipment, no spotter, and no resistance and have significant impact on your fitness.