MariposasSuperset
A superset is when you perform two exercises back to back with little to no rest between them, then rest after both are done. The two exercises can target opposing muscle groups (like biceps and triceps), the same muscle group for extra fatigue, or completely unrelated areas as a time-saving strategy. The key nuance most people miss is that not all supersets are created equal: pairing a chest press with a chest fly hammers the same muscle from two angles and builds serious burn, while pairing a pull-up with a triceps pushdown lets one muscle group recover while the other works, so you actually lose very little performance on either lift. Supersets are popular because they compress training volume into less total gym time, and they tend to keep heart rate elevated, which adds a light conditioning effect on top of the strength work. The common mistake is treating any random pairing as a superset without thinking about how fatigue from the first exercise bleeds into the second, which can quietly tank your form and the quality of your reps.
Example
A lifter doing an upper-body session might pair barbell rows with bench press, resting 90 seconds after completing both exercises before repeating. Because the back and chest work in opposite directions, neither muscle group is pre-fatigued when it becomes the prime mover, so both sets stay productive. Over a 45-minute session this approach can fit in the same total sets that might otherwise take 70 minutes with straight sets.