These drinks are calorie free, which technically should help people lose weight and prevent sugar-related diseases like metabolic syndrome and diabetes. However, the evidence for these beverages having any use is completely nonexistent.
The classic approach to performing supersets is to work two opposing muscle groups back to back without any rest between sets. This technique is usually applied to antagonistic muscle groups such as biceps and triceps, chest and back, quads and hamstrings. An example of a superset would be one set of biceps curls immediately followed by a set of triceps pushdowns.
A superset is performed when two exercises are performed in a row without stopping. When you start doing these for the first time, you will find that your endurance may be a problem, but before long you will learn to love them.