It is neither one nor the other. This is not a question that can stand by its own but has to asked in the context of a goal to be accomplished.
For a body builder, it may be considered necessary to work on that one muscle to achieve overall symmetry.
When I find an imbalance, I may first try to strengthen through isolation before I try to integrate. Here it is a step towards improved function. This is how I personally view muscles isolation. It is not a goal but a means to an end. I believe that it will create dysfunction to only train through muscle isolation.
There is a time and a place for muscle isolation. Many rehabilitation scenarios involve muscle isolation as the practitioner attempts to “rehabilitate” the weakened or injured body part. Exercises such as leg extensions, bicep curls and triceps extensions are staples in therapy clinics. So, depending upon the ultimate goal of the exercise, isolation CAN be, and often is, a “good practice.”
Gus, thank you for your question. It appears we are revisiting a similar question that was posed that asked “Can you really tone your abdominals without doing crunches.”
When I responded to the question I received I believe three negative ratings as a consequence of my response which I will leave again. I was left surprised to hear the opinions of my fellow fitness professionals regarding the function of the rectus abdominis. Gus, I encourage you to have a look at the thread.
Gus, you now ask is “muscle isolation” good or bad. Before I respond, I want to visit the responses that were posted to the question I referred to at the beginning of my post regarding “abs” and “crunches.”
1. One person said, I didn’t know anybody was still doing crunches.”
2 Another highlighted the research he performed on the topic and stated “I don’t do any crunch abdominal exercises.”
3. Another said “it is rediculous to be doing crunches when then function of the “core” is stability and force transference.” He said, “the rectus abdominus does not function by itself and should not be trained in isolation.”
“I think it is important not to forget the function of abdominal muscles. I personally think the word “crunch” is describing one of the actions of the rectus abdominis–flexion of the spine. For me it’s like saying that biceps curls are passe’. When one looks at the direction the muscle fibers are running as well as the origin and insertion of the rectus abdominis, it only makes sense to work the muscle in a “crunching fashion” whether one is standing or lying down. That’s not to say one cannot include eccentric and isometric contractions when training that muscle group.
I personally don’t see anything wrong with performing crunches for that is exactly what the rectus abdominis does.”
I stand by that statement.
Gus, one of things I think that should be considered when responding to to question related to our industry are the populations we work with, the various postures we work with and scope of practice, exercise progression is pivotal to. We might need to isolate a muscle group before we integrate it into a more complex movement. This is a basic teaching in fitness programming. We progress from the simple to the complex.
For many licensed professionals, (physical therapists, occupational therapists) and even some fitness professionals whose scope of practice involves working with populations other than the apparently healthy population muscle isolation may be the optimal approach when it comes to developing strength endurance/strength for that individual. It is important to consider the age, level of conditioning and or whether the individual has mobility issues among other things. I would never ask my oldest client who is 87 to perform a plank. 8((
I work with people in wheelchairs, amputees, stroke survivors, people recovering from traumatic brain injuries and have to use muscle isolation often. Hence, I think there is a place even beyond corrective exercise where muscle isolation fits.
Textbooks such as “Diagnosis and Treatment of Movement Impairment Syndromes” (Sahrmann), “Fitness Programming and Physical Disability” (Patricia D. Miller) highlight specific exercises that isolate muscle group with a specific goal in mind.
Gus, you’ve been posting some really good questions that provoke thought. Thank you for your inquisitiveness. It is helpful to me.
I hope the above is use to you. Have a great day.
I think it’s highly dependent upon your goals and current fitness level. I don’t think isolations are terribly helpful for beginning exercisers as they ought to focus more on compound movements that foster functional fitness.
Isolations are appropriate for intermediate or advanced exercisers who are looking to switch up their training or possibly target weaker muscle groups.
Gus, your question was answerd by more questions? How about a solution? Fixing the startle or withdrawal reflex in the body, will fix the isolation problem so it wont interfere with the chain reaction and the chain reaction wont worry about the isolation, is that simple and it can be done in a matter of seconds. This is what happens when you understand how the human body functions. Hope this helps?