Compound and Isolation Exercises in Strength Training

There are two large categories of movements. Each of these two categories has strong points and weak points. By choosing exercises from one group rather than the other based on your needs, you will make the selection process that much easier.

To construct an effective training program, it’s important to understand compound and isolation movements. These are the two basic types of exercises utilized in weight training. Both movements have distinct characteristics and provide unique options for shaping your physique.

Therefore, all movements (exercises), be they with body weight, free weights, or machines, can be divided into two major categories:

1. basic, compound, or multiple-joint exercises, and
2. isolated, single-joint exercises

Arranging your exercises based on how many joints are involved is similar to arranging them based on muscle size. The more joints that are involved, the more muscle is involved. More joints moving during an exercise also makes the exercise more complicated, and controlling the technique more difficult. It takes more focus and technique to do a tubing stroke exercise, which involves three joints than to do a triceps pushdown, which only involves a single joint. Because the proper technique is key to preventing injury and getting the most out of an exercise, it follows that those exercises that involve the most complicated maneuvers should be done on the front end of a workout.

MULTIJOINT OR COMPOUND EXERCISES

Multijoint exercises or compound exercises (compound lifts) are exercises that work several joints at once. These exercises, therefore, require the coordinated action of two or more muscle groups with motion occurring at more than one joint. Compound exercises are generally similar to the ways that people naturally push, pull and lift objects, whereas isolation exercises often feel a little unnatural.

For example, the squat (bending the legs) forces you to move your knees, ankles, and hips. Three joints are made to work; therefore, this is a multijoint exercise. Determining whether or not an exercise belongs to the multijoint group is a secondary concern, right after you determine which muscles it uses.

Advantages of multijoint exercises

Multijoint exercises are more natural and more effective than isolation exercises. In fact, muscles are made to work together and not one by one in an isolated manner. Multijoint exercises allow you to do the following:

• Stimulate a maximum number of muscle groups (high amount of muscle fibers) in a minimum amount of time (they deliver the biggest payback per training minute). In other words, they build muscle mass fast.
• Manipulate heavy weights. This is because they involve multiple joints and call on more muscles to help move the weight.
• Work within a range of motion where your muscles can easily express their full power.
• Compound exercises involve multiple joints and therefore multiple muscles or muscle groups. In this way, these exercises are better suited for building size and getting stronger.
• These exercises are oriented more toward sports and real-life movements.
• Compound exercises are also more conducive to elevating your heart rate, and to a good calorie burn.
• Stimulate bigger testosterone and HGH production.
• They strengthen the connective tissue supporting your muscles. If connective tissue is substantially weaker than its associated musculature, you are more prone to tendon and ligament injuries, such as pulls, tears, and tendonitis. The connective tissue works in conjunction with your muscles and must be strong for you to progress to higher levels of training.

Disadvantages of multijoint exercises

The popularity of multijoint movements should not overshadow their disadvantages:

• Because muscle mass comes into play, these are the hardest exercises physically. This is why many people avoid these exercises.
• Because of the number of muscles these exercises work, it is not always possible to target the muscles you wish to develop. For example, push-ups use the elbow and shoulder joints. Therefore, push-ups are a multijoint exercise. This movement works the chest, the shoulders, and the triceps. What is impossible to figure out is how much of the work each one of these muscles is performing. For some people, the chest muscles will do the majority of the work. Others will feel only their triceps contracting. Some people will feel it all in their shoulders. So recommending that someone do push-ups to build up the chest could be good advice or poor advice, depending on the individual. There is a random aspect to multijoint exercises that happens much less frequently with isolation exercises.
• In multijoint exercises, the range of motion is less than what a muscle can handle. This range does not necessarily correspond to the range that you need in your particular sport. On the other hand, when you have weak points that resist multijoint exercises, it is often because of the reduced range of motion with which they stimulate the muscle. In this case, only isolation exercises will provide you with the necessary range of motion.

Examples of multijoint exercises

For example, the bench press is a compound exercise that is used primarily to target the pectoral muscles but also involves the triceps and front deltoids. Therefore, the exercise stimulates three muscle groups. It is a multi-joint exercise because the movement involves both arm flexion (the shoulder joint) and extension of the forearm (the elbow joint).

One of many other examples is a rowing exercise for the back, in which both shoulder and elbow joints are initiating the movement.

There are many other examples of compound exercises, especially when it comes to the lower body. The squat, lunge, step-up, and deadlift are examples of compound exercises. They all involve flexion and extension at the ankles, knees, and hips. Squat, for example, is a compound movement because you will mobilize both the knee and hip joints to complete a repetition. As you descend into a squat position, both your knees and your hips bend to allow your body to move downward. Conversely, a leg extension is an isolation movement because you’ll mobilize only the knee joint. While both exercises stress the quadriceps primarily, they apply stimuli to different areas of the lower body.

Most variations of the squat stimulate all the quadriceps muscles and provide secondary stress to the gluiest and hamstring muscles. In effect, your entire lower body has to work in this exercise (and, due to the stabilization required, even many muscles in the upper body).

On the other hand, the leg extension stresses the quadriceps muscles, particularly the vastus muscles, almost exclusively. Virtually no stress is applied to the hamstrings and glutes. As you can see, understanding compound and isolation exercises is important to your training goals.

By tradition, compound (multijoint) exercises are considered strength builders, and isolation (single-joint) exercises are favored for shaping muscles. To provide your muscles with the ideal stimulus, your exercise regimen should include both types of exercise.

ISOLATION OR SINGLE-JOINT EXERCISES

As the name suggests, an isolation exercise (or single-joint exercise) isolates one muscle and typically involves motion at one joint. For example, biceps curls (movement of the forearm over the arm) involve only the elbow joint. Even if this exercise is often described as a multijoint exercise for the arm, that description is technically incorrect.

While isolation exercises focus on just one joint or muscle, the name is a bit misleading because you can never truly isolate a single muscle. Nevertheless, it’s a pretty common term that you should be familiar with.

Most isolation exercises involve machines rather than dumbbells and barbells (free weights).

Advantages of single-joint exercises

• By using fewer muscle groups at one time, isolation exercises use less strength and energy. They are therefore much easier than multijoint exercises.
• These exercises are best for working specific hard-to-grow muscles or to specifically isolate a particular muscle.
• Isolation exercises target muscles better than multijoint exercises. In general, it is difficult not to feel a muscle targeted by an isolation exercise.
• Isolation exercises are better for developing muscle control.
• They are easier to learn and execute using good form.
• If a muscle is not developing with the use of multijoint exercises, a few weeks of training with isolation exercises can wake it up. When you begin doing multijoint exercises again, you will feel that muscle working more. The muscle will then begin to respond to the work required by exercises that involve multiple joints.
• They put less stress on the connective tissue than do compound movements. Because the amount of weight that you can utilize is substantially less than for compound movements, isolation exercises reduce the tension applied to the joints. This can be of particular benefit when you are training around a previous injury or medical limitation.
• They are more appropriate for developing smaller muscle groups. For smaller muscle groups such as the biceps and triceps, most exercises involve only one joint (the elbow in this case). You can train triceps by doing close-grip bench presses and dips, both compound movements, but you’ll find that virtually every other triceps exercise is a single-joint move.
• A lot of isolation work usually is needed by competition-level bodybuilders who are already very big and strong, and who want to add “spit and polish” to their physiques.
• Isolation exercises tend to be better for developing muscular symmetry.

Disadvantages of single-joint exercises

• Generally, isolation exercises are less effective than multijoint exercises in increasing strength and size.
• Muscle isolation is an artificial phenomenon. When you perform work requiring strength, your muscles are made to work together, not in an isolated fashion.
• If you tried to reproduce the work performed by multijoint exercises only with isolation exercises, you would waste a lot of time. For example, instead of doing a few push-ups, you would have to do a chest exercise plus a shoulder exercise plus a triceps exercise.
• The greater range of motion in isolation exercises does not allow you to use as heavy a weight as you would use in multijoint exercises.
• Don’t stimulate anabolic hormone production.
• It takes a long time to work all the muscles that you could train using only single-joint exercises.

Examples of single-joint exercises

For example, the dumbbell flye is an isolation exercise that is used primarily to target the pectorals. The elbows are kept at a fixed angle throughout the range of motion and so no other muscle groups are worked. It is a single-joint exercise as it only works around the shoulder joint.

There are so many popular isolation (i.e., single-joint) exercises such as leg extensions, leg curls, laterals, pec deck work, triceps kickbacks, and cable crossovers, etc.

THE MOST EXTENSIVE LIST OF EXERCISES CATEGORIZED AS A SINGLE-JOINT OR MULTIJOINT MOVEMENT

Visualize each exercise and try to understand why it is considered a single- or multiple-joint movement. Once you are familiar with the difference, you’ll be able to determine the type of almost any exercise and apply it properly in your routine.

Machine exercises categorized as a singe-joint or multijoint movement

Free-weight exercises categorized as a singe-joint or multijoint movement

Alternative-equipment exercises categorized as a singe-joint or multijoint movement

Summary and conclusion about multijoint and single-joint exercise

As a rule, compound movements involve the action of two joins, while isolation movements involve only one joint. Consequently, many supporting muscles are involved in the completion of a compound movement. Certain compound movements, such as the Olympic deadlift, require the use of virtually all of the major muscles of the body. In contrast, isolation movements tend to target a specific muscle or muscle group, excluding secondary muscles. Because only one joint is used to lift a weight, supporting muscles are less active during exercise performance.

Each type of exercise has its uses. The type of exercise performed also depends on the individual’s goals.

Programs for beginners (where overall development is of prime concern) should primarily be made up of multijoint exercises. They help to develop your proportions in a way that would be impossible solely by using isolation exercises. These allow for intense work on a maximum number of muscle groups in a minimum amount of time. Isolation exercises can later be added to these multijoint exercises in order to target certain areas that are delayed or that you really want to focus on.

Isolation exercises are secondary and are mainly for people searching to enhance their appearance. They are very useful for “rounding out” a routine, by directly exercising muscle groups that cannot be fully exercised in compound exercises. In fact, as we have already seen, multijoint exercises do not necessarily stimulate all the muscles they are supposed to work in an equal manner. Certain groups will take precedence over others. Isolation exercises can help you maintain balance.