Circuits
If you are an extremist you can take supersets to a another level without resting during your entire workout. This method is brutal but very rewarding. Like supersets, exercises focusing on opposing muscle groups can be done back to back with no rest included. During a circuit you can alternate each exercise you have planned for the day with no rest until you are done. This can be done with just two muscle groups back to back such as biceps and triceps, or you can do a more traditional approach such as full body alternating each muscle group. Whichever you choose this is sure to keep your heart rate up the entire workout and to cut down on gym time.