What Are Reps and Sets and Why Are They So Important?

Reps and sets are the building blocks of structure and organization for your strength workouts.
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When you're starting a new workout plan, it may feel like you're hearing a whole new language. After all, you probably haven't heard about reps and sets in the office or at the supermarket.


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But sets and reps will quickly become part of your vocabulary. These concepts help you organize and structure any exercise routine and can help you track your progress and improve.

What Are Reps?

Reps is short for repetitions, or the number of times that you perform any given exercise in your workout. If a fitness instructor or an online training plan tells you to do 10 reps of a body-weight squat, that means you'll repeat the exercise 10 times.


Each rep of an exercise puts your muscles through several positions, including a lengthening phase, a contraction phase and a shortening phase, according to the American Council on Exercise (ACE).

The different muscle positions of each rep is easy to visualize with a biceps curl. As you curl a dumbbell up to your shoulder, your biceps shortens and contracts. Then, as you lower the weight down to your side, the muscle lengthens. All of this action happens in just one repetition.


Most exercises are performed in a range of 8 to 12 reps total per set (more on sets below). This range is best for general increase in muscle strength and size (aka hypertrophy), according to the ACE.

On the other hand, to build muscular endurance, you'll want to keep your reps high, between 20 to 30 repetitions, according to the ACE. Higher rep ranges are excellent for runners or cyclists who need to perform exercises for long periods of time without muscle fatigue.


Generally the amount of repetitions you perform should be inversely related to the weight you're lifting, the ACE recommends. If you're performing heavy squats, for instance, you may want to do just 6 reps. On the other hand, if you're doing light hammer curls, you can go for 12 reps total.

Whether you're training for hypertrophy or muscular endurance, you want to perform your reps to a point of muscular fatigue, which is when you feel too tired to do one more repetition with good form.

That number will be different for everyone, Carolina Araujo, certified personal trainer, tells LIVESTRONG.com. For some people that's 10 reps, while for others it's 15.

Reps Recap

Reps = the number of times you perform a given exercise

What Are Sets?

The sets in a workout tell you how many times you will repeat a particular number of repetitions of a given exercise. Let's say you're doing triceps kickbacks. Two sets of 15 reps means you'll perform 15 kickbacks two times total, resting between each round. In total, you'll be doing 30 kickbacks.

As with the reps you do, you can also tailor your sets to your personal fitness goals. Araujo suggests performing each exercise for about 3 to 4 sets if you're looking to improve your body composition. To build muscular endurance, you can even go up to 5 sets, she says.

No matter your personal training goals, you want to keep your sets manageable, just like with your reps. Perform enough sets to fatigue your muscles but make sure to prioritize good form over the amount of exercises you do.

Sets Recap

Sets = the number of cycles of reps you complete

Use Reps and Sets for Organization and Structure

Sets and reps provide organization and structure to your workout. Along with the amount of weight you lift, these elements make up your overall training volume.

Week to week, you can tweak these elements to create a progressive overload, which is the process of gradually intensifying your workouts (by adding more sets or reps or more weight) to effectively build muscle.

As you create a progressive overload in your training regimen, avoid ramping up the sets or reps too quickly. A little soreness post-workout is normal, especially if you're trying new exercises. But if you increase your training volume too aggressively, you may experience some serious soreness and even run the risk of getting injured.

Instead, increase your weight, sets or reps little by little and monitor how your body feels each day. While your ego may drive you to stack on as much weight as possible, Araujo says, always prioritize your form to stay safe while training.