A set is group of repetitions performed for an exercise. Determining the number of sets to be completed of a particular exercise has tremendous impact on the physiological adaptation and response to the exercise. Sets can range anywhere from one to more than ten depending on the goals and needs of an individual. 

The more sets you perform, the more stress you create, which, with adequate recovery, will create better results. However, just doing more sets, in hopes of better results, without adequate recovery will increase the likelihood of over stressing your body, which will greatly diminish results. 

Determining the number of sets to perform sets to perform will be dependent on your current level of fitness, your goals, and the exercise being performed. Choosing the number of sets to perform should also factor in the concept of volume for each exercise, and the overall training session. In general, two to five sets is appropriate for most exercises and most individual’s goals.