What you need to know about fitness strength training for a strong lean body that both looks good and is resistant to injury.

Down at the gym there is one type of question I hear guys asking their personal trainers all the time that shows that many people are missing the big picture regarding the benefits of strength training. This question usually goes something like this:

“What exercise can I do to isolate my – (triceps, quads, abs, biceps, etc)?”

It doesn’t matter which muscle someone is asking about, they always seem to want to ‘isolate’ it.

The first question you have to ask is: “Why in the world would you want to isolate it?”

The first thing you need to understand is that the body was not designed to work in muscle isolation. Rather, it works better in movements along a kinetic chain; i.e large portions of the body assist other portions of the body in completing a complex movement. In fact, there really is no such thing as true muscle isolation. There is always an associated muscle group that will help in some way with whatever movement you are doing. This article compares attempting to ‘isolate’ body parts via single-joint exercises to the much more effective strategy of performing multi-joint complex movements.

When you attempt to ‘isolate’ muscles by performing single-joint exercises, you are actually creating a body that does not function correctly and will be more prone to injury. Essentially, you are creating a body that is a compilation of individual body parts, instead of a powerful, functional unit that works together.

Now if you really want to end up with joint problems, tendonitis, and excess body fat, then go ahead, continue trying to ‘isolate’ body parts. On the other hand, if you would rather have a lean, muscular, injury-free, functional body that works as a complete powerful unit to perform complex movements (in athletics or even everyday tasks), then you need to shift your focus away from muscle isolation.

Focusing on how well your body functions will give you the side effect of a body that looks even better than it would have if you focused on muscle isolation. For example, take a look at the bodies of any NFL running backs, wide receivers, or world class sprinters. These guys pretty much NEVER train for muscle isolation (their strength coaches won’t let them!), yet they are absolutely cut! Just look at athletes like Terrell Owens or Maurice Green and tell me who wouldn’t want a body like those guys.

Another major benefit of moving from the ‘muscle isolation’ mindset to a more ‘complex movement’ mindset is that you will find it much easier to lose body fat. The reason is that by focusing less on single-joint isolation lifts and more on multi-joint complex movements, you not only increase the number of calories you burn during each workout, but you also increase your metabolic rate, and stimulate production of more fat burning and muscle building hormones such as testosterone and growth hormone.

Here’s an example. The machine leg extension is a single joint exercise that works mainly the quadriceps, can potentially cause knee joint injuries in the long run, and doesn’t even burn that many calories. On the other hand, exercises like dead lifts, squats, step-ups, and lunges are all multi-joint complex movements that work hundreds of muscles in the body (including the quadriceps) as a functional unit, create more stable and strong joints in the long run, and also burn massive quantities of calories compared to the single-joint exercises.

Now even though I feel that multi-joint exercises should comprise the majority of your weight training workouts, there can also be some benefits with just minor inclusions of single-joint exercises for variety, etc. I like to build my training programs with about 90-95% multi-joint exercises and about 5-10% single-joint exercises at most.