In the last few weeks, and more after Friday’s bicep curls, I’ve had questions of why all the single joint movements and how do these movements fit into the CrossFit methods.  I mentioned it briefly in the post before we began the strength, but I’ll further explain here.
I am obviously aware many CrossFit purists will say single joint movements are not “functional”  and typically do not mimic movements humans perform daily.  But I contend any CrossFit “purist” should be able to recognize that by incorporating single joint movements in programming is, by definition, varied and certainly broadens the modal domains in which we perform work.  Furthermore, if a program incorporating single joint exercises increase our capacity for work by correcting and addressing imbalances and increasing strength, how can it be anything but CrossFit?  How could anyone, except the sexy MetCon lovers, argue it not a good thing?

But before I get to it, I’d first like to line out definitions and some terminology in regards to the different types of movements.  That will get us all on the same page and help clear up any confusion that accompanies miscommunication.  I know sometimes me being a stickler for definition seems like I’m splitting hairs, but with proper definition often comes a certain mindset and with mindset also comes context and perception.

Compound Joint Exercises

Daniel demos excellent squat technique... A2A, babell over the heels, head and chest up, knees in line with toes, ankles, and hips.

Compound exercises, or full body exercises, are movements that place stress on multiple muscles or muscle groups at once in involve more than one joint.  An example is the squat.  Performing a squat engages the muscles in the lower body and mid-line.  Squats, performed correctly and with a respectable load, recruit muscle activity and support from every muscle in the body.  It is,without question, a foundation exercise in any decent training regimen.

Isolation Exercises
Isolation exercises…  ok, let’s clear this one up…There is no such thing as an isolation exercise. It is impossible to perform a movement and only involve one muscle of the body.  Even in a preacher curl, there are many muscles other than the biceps engaged.  When you did your first DB Bent Over Rows, were your obliques sore?  They should have been.

The better term is single joint exercise.

Single Joint Exercises

Single Joint exercises work only only one joint at a time and tend to give focus to one muscle or a small group of muscles married into performing one function.  They are most often, or at least most often thought to be, used by the bodybuilding camp to induce hypertrophy.  However, single joint exercises are just as

frequently used to correct a specific muscle weakness or imbalance.
Another important (especially to athletes) and very overlooked benefit of single joint exercises is the increased ability to fire the muscles involved.  By giving one muscle group focus, the CNS will learn to control that muscle more efficiently.  In other words, a bicep curl teaches you to fire the bicep more effectively.  By learning to fire the biceps more effectively an athlete can recruit the biceps more in a pull up and therefore, increase the numbers and quality of your pull ups.  In a stiff legged deadlift, the focus is on the hamstrings.  By strengthening the hammies correctly and developing proper balance between them and the quadriceps, our squats, pulls, running, cleans, snatches, and almost ever other movement will improve.

An excellent example, and one CrossFitters will be more apt to identify with and appreciate, is if your subscapularis is underdeveloped,

Performing only full body movements can somtimes lead to imbalances in muscle groups and weaknesses in muscles vital to performing full body movements.

your overhead squat will suffer.  The subscapularis supports the shoulders (this applies whether you are of the “active shoulders” or “shoulders drawn back” schools of thought) in all overhead movement and especially in supporting weight locked out overhead.  Even if you have a great overhead squat, press, and snatch, but your shoulders are imbalanced, think about how much you would improve once you’ve trained all the muscles in the group to fire at maximum potential.

After doing the tricep extensions last week, lifters who had previously done single joint/split routines reported a “disconnected” feeling and a lack of control over their triceps.  The extensions will reteach the triceps to engage with more power.  In a shoulder press, push press, or thruster, it will translate into more power to complete the movement.  Noted were also fatigue in the shoulders and lower back while doing the overhead extensions…  again, there’s no such thing as an isolation exercise.

A quick caveat though…  a single joint exercise must be done with the same level of focus and intensity as a max effort squat or deadlifts.  A set of lateral raises or DB shoulder presses… even bicep curls, should leave you gasping for air and taxed… just like squats or deadlifts do.

So, we do both compound joint and single joint exercises.  Using them properly, and in conjunction with each other, is where we can make the most of our training.  Performing too much of either can cause imbalances and derail your fitness goals.