Biceps and triceps supersets, in which you alternate biceps and triceps exercises without rest, work really well. A good, basic superset for arms is the barbell curl alternated with the cable triceps pressdown. Take the barbell to the cable machine, that way you eliminate any rest between sets. This really helps to maximise the blood flow into your arms. A lot of bodybuilders have built great arms doing this kind of superset.
The delts are more like the endurance muscles you see with calves or forearms and they can handle more reps. Some athletes who are really gifted can do heavy barbell or dumbbell presses and just grow easily. If you have problems gaining size try giant sets (where you combine 4-5 exercises and complete them consecutively with no rest between). It is really intense and you will feel a killer pump on your shoulders. Do a giant set with dumbbell lateral raises, dumbbell shoulder presses, upright rows and bent-over lateral raises for 10 reps each exercise, or 40 reps to total. If your shoulders are not responding from heavy training, this type of advanced supersetting will really work.
This all depends on how long you have been training for. Basically, advanced techniques like forced reps or drop sets can be used about 3 months after you have started training because that is when you typically hit a plateau. So if you feel like you need something changed, if strength or muscle gains have come to a halt, then advanced techniques may be good for you to try. Forced reps, where you have a training partner help you through a few additional reps after hitting initial failure, are a good place to start as long as you do not overdo them.
1) Perform an equal number of exercises with the same relative intensity between opposing muscle groups (eg, back and chest, hamstrings and quads, biceps and triceps). If you already have a deficit, try to do more sets on the weaker/disregarded bodyaprt until you have achieved better balance. Then train bodyparts equally.
2) To bring your training into balance, focus on isolation (single-joint) exercises while also modifying the compound movements that target the various muscle groups. For example some exercises, such as the squat and leg press, are generally regarded as quadriceps moves, even though they absolutely involve the hamstrings and glutes. However, by altering foot placement (wider, higher on platforms etc.) you can shift the emphasis to the less involved hamstrings.
3) If you have an existing deficit between opposing muscle groups, spend some extra time stretching the stronger muscle group and strengthening the weaker one.
4) If you find a specific bodypart to be particularly stubborn at responding to an adequate training stimulus, consider adding an extra day (or two) specifically dedicated to working the stubborn bodypart until it catches on.
Competitive bodybuilders usually train for symmetry and proportion in an effort to build an aesthetically pleasing physique. There are many individuals who go to the gym to build up their beach muscles, disregarding symmetry and proportion in designing their training programs. Instead of training opposing muscle groups equally, they sometimes ignore the muscles they cannot see (back, hamstrings, calves, quads) and focus on the muscles they admire in the mirror everyday (chest, biceps, shoulders and abs). Although training specific muscle groups more than others can create an unbalanced-looking physique, disregarding a muscle group over time can potentially lead to other problems that may subject the body to injury.
One common mistake with regard to balanced training is performing an unbalanced training program between the chest and back muscles. The amount of time, energy, effort, volume and frequency between the agonist chest muscles and the antagonists back muscles may not be equal, or even close. A simple example would be an athlete who performs 4 sets os four exercises for the chest (for a total number of 16 sets) and does only 3 sets of three exercises for the back (for a total number of 9 working sets). Following this unbalanced training regime over time will result in back muscles much weaker than the chest muscles. This imbalance may lead to a slightly kyphotic posture (forward/rounded shoulders) that can potentially cause shoulder problems because of the faulty posture. In addition to the stronger chest muscles (compared to the back muscles) pullong the shoulders forward, inadequate stretching of the chest musculature can further contribute to this problem.
For some people, training legs consists of quads and that is it. The disregard their hamstrings while training only the quadriceps. Exercises such as the leg extensions, hack squats and front squats place a large amount of emphasis on the quads. Although these exercises are great you need to do an equal amount of hamstring work with leg curls and romanian deadlifts to stress both muscle groups. Distributing attention evenly to both muscle groups can give you healthier knees and lower back, as well as fewer hamstring strains because of an unbalanced hamstring-to-quad strength ration.
A less obvious training error woth regard to balanced training concerns the shoulders. Overhead shoulder press, incline bench press, flat bench press and other chest and shoulder pressing movements are critical for maximal muscle development. However, these exercises focus on the major muscle groups such as the deltoids, pectoralis major, pectoralis minor and other muscles known as prime movers. Often ignored in a training regime is the training or isolation of the smaller muscle groups in the shoulder known as the rotator cuff (the supraspinatus, infraspinatus, teres minor and subscapularis) that are critical in keeping the upper arm in the socket of the shoulder. Failure to train these smaller muscles groups, two of which are not even visible can create an imbalance between the large prime movers and small stabilisers. This lack of imbalance in strength may result in bursts of bursitis, tendinitis or even rotator cuff tears in the shoulder joint.