The first step of designing an effective resistance training program is to select exercises with the greatest effect on muscle gain.
Exercises can be categorized as either single-joint (isolation) or multi-joint (compound) exercises.
There has been a great deal of debate and controversy over which type of exercises (isolation or compound) lead to better muscle growth. Well, in this post you will find out the truth about isolation and compound exercises and how both should be utilized for best results.
Isolation exercises are single joint movements in which only one muscle group is trained alone. These exercises are used to “isolate” single muscle groups with minimal involvement from other supporting muscles.
Some examples of isolation exercises would be:
- Bicep curls
- Preacher curls
- Leg extensions
- Calf raises
- Triceps extensions
- Peck Machine Fly’s
- Lateral raises
Typically, if an exercise involves curling, raising or extending, it’s usually an isolation exercise that targets one major muscle group. All of the above exercises isolate single muscle groups through movement at one joint.
You can see this with biceps curls, where the weight is curled up with only the contraction of the biceps muscles and movement at only the elbow joint.
Why Isolation Exercises are Important
The specific muscle isolation provided by this type of exercise allows you to apply direct isolated tension on a single target muscle. This is beneficial in the case of “hypertrophic imbalance” (greater growth in some muscles than others), selectively targeting smaller, weaker muscles can improve symmetry, leading to not only growth of the target muscle but greater functional strength.
Another advantage with isolating certain muscle groups is that you can train the muscle through its full range of motion to a maximum degree.
For example, to really develop your biceps you would need to perform isolation exercise such as dumbbell curls, because there are no compound exercises that primarily target the biceps.
Examples of compound exercise that recruit the biceps muscles would be underhand grip rows, pullups and pulldowns. The problem here is that the primary working muscles in these exercises are the back, with the biceps working secondarily.
In this case, to maximally work the biceps, isolation exercises such as curls are required.
Isolation exercises also help to develop a better mind-muscle connection. The more efficiently you can call on a muscle group to work, the better you will be able to fire muscle fibers and develop that muscle. Your muscles are connected to your brain by nerves and a strong connection helps you mentally control the amount of force you can generate on a given exercise.
Isolation exercises allow you to really focus your attention on a single muscle at a time, leading to better target muscle development.
Finally, the addition of isolation exercises in a workout routine allows you to work a muscle group more thoroughly, by training it through different points of the strength curve.
There are three main kinds of strength curves – Ascending, descending, and bell shaped. Every exercise has what is called a strength curve that creates more or less resistance at different points of the movement. To maximally stimulate a muscle its best to train it through all points of the strength curve.
The only way to effectively train all muscles through different points of the strength curve is by using a combination of isolation and compound exercises.
To cover all muscle groups and exercises that target all the strength curves in great detail would take up a whole post in itself. But I cover this factor in more detail in the
“Optimum Mass Workout Programs” eBook (no longer available). If you are following the main Optimum Mass 12 week workout program you don’t need to concern yourself with strength curves, I’ve got you covered.
Compound exercises are multi joint movements that involve the use of more than one major muscle. These exercises target one major muscle group but recruit several other smaller muscles secondarily.
Some examples of compound exercises would be:
- Dumbbell or barbell bench press
- Lat Pull-downs
- Pull ups
- Deadlifts Squats
- Overhead Shoulder Press
Typically, pulling, pushing or deadlifting are compound exercises that train more than one major muscle group at a time. The above listed exercises are compound movements that work more than one muscle group through movement at more than one joint.
The bench press is a good example of a popular compound exercise. The primary target muscle in this exercise is the chest but the shoulders and triceps muscles are also heavily involved. The bench press works both the elbow and shoulder joints, making it a compound exercise.
Why Compound Exercises are Important
As previously mentioned, isolation exercises have definite benefits, but consider them secondary, not primary, movements. Effectively training to gain muscle mass means your routine should largely consist of compound movements, which are widely considered and research proven more effective muscle builders because they recruit greater amounts of muscle fiber overall, allowing for more weight to be lifted.
Furthermore, this larger muscle-recruitment positively impacts how anabolic hormones (muscle building hormones) respond to training.
Post-exertion hormonal elevations correlate with how much muscle mass was involved in the exercise. As shown in the study “The importance of physiologically elevated hormone levels”, in the Scandinavian Journal of Medicine & Science in Sports, and the study “Acute hormonal responses in elite junior weightlifters”, in the International Journal of Sports Medicine, compound exercises produce greater increases in growth hormone and testosterone levels than isolation exercises.
GH (growth hormone) and testosterone are potent muscle building hormones.
Compound exercises tend to require signiﬁcant stabilization of the entire body, thereby involving numerous muscles that otherwise might not be stimulated with isolation exercises.
A training session always starts with compound exercises performed first, followed by isolation exercises. Compound exercises are more physically demanding and performing them first means you will have the energy to perform these exercise with maximum intensity, resulting in greater release of anabolic hormones and greater overall workout intensity.
For maximum overall muscle development both isolation and compound exercises must be used.
You can find a list of the best muscle building exercises for each muscle group in the “Optimum Mass Workout Programs” eBook.