I’m sure there have been many times in the gym where you have seen people just using machines for isolation exercises and not really doing compound lifts like squats, deadlifts and bench pressing exercises. You also see other people just focusing on those heavy squats and compound lifts yet not doing the isolation exercises like the leg extensions or the pec deck butterfly. Let’s examine this major issue between compound vs. isolation exercises. What is better?

What is a compound exercise? Compound exercises are multi-joint movements that work many muscle groups at once. A great example of a compound exercise is the squat. The squat not only works every muscle group of your legs (quadriceps, hamstrings, calves and glutes), but also works your core, lower back, traps and other muscles.

What is an isolation exercise? Isolation exercises target one muscle group and only one joint at a time. An example of an isolation exercise is the quad extension, which only hits the quadriceps.

To fully stimulate the muscles, you should incorporate both compound and isolation exercises. Nevertheless, if your main goal is to build muscle, you should focus on compound movements and use the isolation exercises as secondary or a supplement.

Each muscle group is supported by many other muscle groups that work together to lift that weight in the gym. For example, let’s say you are working the chest and doing bench press, one of the best compound workouts. You are the strongest (and thus more prone to grow muscle) when you not only have a strong chest for the bench, but also you have strong shoulders and triceps as well as strong back muscles to support the weight and strong legs to power through the movement as well. Therefore, when you keep working on the bench press, you are also training the shoulders and back and all the interconnecting but smaller muscles in between. When all these muscle groups work together, you are able to lift and grow more.

In addition, compound movements place the greatest stress on your muscles, which in turn stimulates the endocrine system for more hormonal release, which is vital to muscle growth. Compound movements also keep a muscular balance in your body. If you are only isolating one muscle then that muscle you isolate will grow stronger than the surrounding muscles. Your surrounding muscles can no longer support your stronger muscle and may lead to more injuries. For example, if you are doing quad extensions and isolating your quadriceps more than any other part of your legs then what will happen when you squat? Your quadriceps may be able to handle heavy weight when you squat but your hamstrings are more likely to give out because it is not as strong or adapted to handling the same weight as your quads are. In terms of leg training, you want to focus on compound movements like the squat or leg press because each part of your legs will adapt to the stress placed on them through these exercises. The same exact mentality should be placed on all the muscle groups.

So to answer the question as to which are better to promote muscle growth and for injury prevention, compound movements come out on top. Nevertheless, if you want to fully maximize lean muscle mass, you have to incorporate isolation exercises with compound exercises. Isolation exercises allow you to “sculpt” a specific muscle. You can build up your chest through bench press but what is going to differentiate you from another muscular guy? You need to do isolation exercises to visually separate your muscles from one another and promote muscular symmetry. Think of your body like a statue: The giant piece of marble is from doing compound exercises; it is essentially your foundation. Nevertheless, each piece of marble is “sculpted” to make it different from one another, giving it extensive details by doing isolation exercises.

You should always do compound exercises in the first part of your workout and end with isolation workouts. Isolation exercises should be used later in the workout to completely fatigue muscles after the compound exercises have taken place. Isolation exercises specifically target one muscle the best, meaning more blood flow is directed at that muscle. Blood flow is directly correlated with muscle growth because blood transports essential nutrients to the muscles for growth.

Popular Compound Exercises

Shoulders: Military Press, Arnold Press, Hang Clean and Press

Biceps: Close-Grip Chin-Up (w/ palms facing toward your face), Standing Barbell Curl

Triceps: Close-Grip Pushup, Dips, Close Grip Bench Press

Legs: Stiff Legged Deadlift, Barbell Squat, Lunges

Back: Deadlift, Row, Pull-Down, Pull-Up, Renegade Row

Chest: Bench Press, Dips, Pushup, Incline Dumbbell Press

Popular Isolation Exercises

Shoulders: Side Lateral Raise, Front Dumbbell Raise

Biceps: Seated Dumbbell Curl, Cable Concentration Curl

Triceps: Triceps Rope Extension, Skull Crushers

Legs: Quad Extensions, Lying Leg Hamstring Curls, Donkey Calf Raises

Back: Seated Row, Rhomboid Cable Squeeze, Alternating Cable Pull, Lat Pulldown

Chest: Pec Deck Butterfly, Flat Bench Dumbbell Flyes