Reps Versus Sets: What's The Difference?

Whether you're new to the gym or diving into the world of at-home exercise, there is a whole lot of jargon to learn. Aerobic versus anaerobic, cardio and HIIT, not to mention the different theories on which type of exercise is best for the goal you have in mind. Before you dive that deep into your fitness routine, however, there are a few terms you need to know — ones that make up the foundation of most fitness routines. The words "rep" and "set" are two critical ones.

As Reference states, "rep" is short for repetition. Fittingly, it's the number of times you should repeat any given exercise. If you're working out your arms, for example, and you do 15 bicep curls, you have done 15 reps of the bicep curl, or 15 repetitions. Livestrong says that most workout routines are structured around 8-12 reps. Most of the impact from your workout is due to the way reps affect your muscles. The American Council on Exercise states that there are several phases to each rep. Such phases include the lengthening phase, the contracting phase, and the shortening phase. Each one is integral to the exercise and leads to the expected results, but what makes reps different than sets?

Sets differ from reps in that they aren't a single action. Instead, they are made up of multiple repetitions, according to Reference. If each bicep curl is a rep, then the group of 15 that you did is equivalent to 1 set. Each set is separated from the others either by a rest period or by another set of different exercises, depending on the type of workout. This is more or less the basis of High-Intensity Interval Training, or HIIT. A HIIT routine consists of several sets, each with a certain number of reps. The sets are separated by rest periods so people can put as much energy as possible into each rep (via WebMD).

Livestrong interviewed Carolina Araujo, a certified personal trainer, for her recommendations on sets and reps. She suggests doing no more than 3 or 4 sets if your goal is to change your body composition. If you want to improve muscular endurance, you can go as high as 5 sets. Of course, sets and reps aren't the only components of a workout, but they make up a solid foundation for every fitness routine.