Walk into any gym or fitness center across America, and you are immediately inundated with numerous options to meet your fitness goals. As you begin to scan your surroundings, you take notice of the often times countless number of machines, as well as rows of free weights. Often times this can seem overwhelming, particularly for those who are new to the fitness environment.
Often times people are nervous or apprehensive to exercise in front of others, in fear of either doing something wrong, or worse more, standing out like a sore thumb. So this situation presents the question, should I use some of many machines at my disposal, or choose free weights to meet my goals.
To answer this question, we need to take a quick peak into how the body functions from a bio-mechanical perspective, and whether or not machines or free weights fit our unique patterns of required movement. To keep this task simple, we can see that the body does not move or function independently, but rather within and integrated pattern where muscles work together to produce movement. These patterns are called force couples, and this simply means that numerous muscle groups work as a team to accomplish a specific movement.
For example, on the often used bench press, the prime mover is the pectorals major, however, it's primary helpers are the anterior deltoid and all three heads of the tricep. Along with this, the rotator cuff muscles help stabilize the glenohumeral joint in order to stabilize the shoulder and produce the movement. As we can see, movement simply cannot happen without the contribution of numerous muscle groups, all of which have a job to do in order for a movement to take place.
What does all this have to do with free-weights and machines when choosing a resistance program, well the answer is everything. When we choose a machine to target a muscle, we are working that muscle in isolation, which is not how the body functions while doing everyday movements. This is key because when a muscle is repeatedly worked in isolation, the force couples are decreased or often times taken away altogether. Why does this matter you may ask, well when we begin to isolate a muscle, our nervous system picks up on this change, and begins to think that this is the way the muscle should always function, particularly when this is when it has the most stress placed upon it.
After a period of time that consists of this isolated muscle training, our force couples begin to change. Picture you and a friend carrying a couch down a flight of stairs, if either one of you decides take a little less of the load on their end, the other one has to pick up some of the slack. Thats the way it is when we begin to isolate, the stabilizers or helper muscles do not have to be activated simply because the machine is doing that part for them. Over time, our natural integrated pattern of movement is thrown off, meaning some muscles are doing their job and some are not. The end result is always a slowly developing injury mechanisms, stemming directly from incorrect force couples during loaded movements.
With free weights, we take the same movement patterns as the machine is dictating, but this time our force couples are used correctly in order to stabilize and assist within the movement. This also means more calories burned, since all the muscle groups are working together to complete the movement. This also means that injury opportunities go down because all of the muscles involved within the exercise are adapting to the movement together and not independently of one another.
Bodyweight exercises, TRX, and other synergistic movement patterns are similar in there approach to including proper force couples, so no matter whether you are a beginner or a season lifter, the choices are unlimited. If you do decide to include machines in your workout, simply put them at the latter half of the program, this way the stabilizer and helper muscles have been included, and now its ok to give a little extra attention to only the prime mover. The take home message is that free weight or integrated bodyweight movements are always best, not only from a performance and results perspective, but more importantly from and injury prevention standpoint.