Compound exercises are multi-joint movements that work several muscles or muscle groups at a time. For a healthy athlete or anyone who is trying to get the most out of a training program, compound exercises are generally preferred and recommended.
Why Use Compound Exercises?
There are many reasons to use compound exercises during a workout. They include (but aren’t limited to) the following:
•More working muscle groups means more calories burned during.
•They simulate real-world exercises and activities.
•They allow for a full-body workout faster.
•They improve coordination, reaction time and balance.
•They improve joint stability and improve muscle balance across a joint.
•They cut down on the risk of injury when playing sports.
•They keep up the heart rate and provide cardiovascular benefits.
•They allow for longer sessions with less muscle fatigue.
•They allow for lifting of heavier loads and build more strength as a result.
Compound movements that are extremely heavy are said to have the greatest degree of leverage. When possible, they should be used in preference to simple, single-joint movements when the goal is optimizing increases in both size and strength.
In contrast, isolation exercises are meant to work only one muscle or muscle group and only one joint at a time. They do have their place and are a widely accepted form of exercise. Examples of isolation exercises include the biceps curl or the quadriceps extension. These exercises are often performed with the commercial weight machines. The goal is to isolate one muscle group and move from one machine to the next until one “works” the whole body. Isolation exercises are frequently used in physical therapy clinics and rehabilitation centers to address a specific muscle weakness or imbalance that often occurs after injury, illness, surgery or certain diseases.
“Isolating’” a Muscle Group
Although it might seem like a matter of semantics, the strict isolation of a muscle group of the sort used in resistance training is an anatomical impossibility. This is because one muscle cannot function on its own—there are always at least two muscle groups in every involved in every movement, an extensor muscle, which “opens” the joint (i.e., increasing the angle between the two bones) and a flexor muscle, which does the opposite to an extensor muscle. All muscle fibers run the complete length of the respective muscle group, from the origin (the point closest to the midline) to its insertion (the point farthest from the midline). These muscles receive growth stimulation along their entire length, so it is not physiologically possible to “shape” a muscle inasmuch as the structure and form are genetically determined.