Ever wonder why your knee seems to flare up whenever you start running? Or maybe it’s your shoulder that starts to go only after a couple repetitions of chest flys? Well, I’m here today to put some food for thought on your plate on the ideals surrounding two popular exercise principles, load sharing and isolation.
To begin, we need a rough idea of what defines both of these principles.
Load sharing vs. Isolation: Defined
The easiest way for me to describe this form of movement is from a functional standpoint. In a compounded movement (when two or more muscle groups work together to perform a movement i.e. back step lunge) the load or weight of the exercise is spread across multiple joints or levers. This helps to “share” the load and ultimately I have experienced more efficient use of movement in general application when coaching this style of movement. This, as one would imagine is incredibly beneficial for folks that are looking to become more functional and efficient at completing daily tasks. 90% of the people I have the privilege of working with are in this category. Makes sense? Your body can use more of itself to help decrease the strain on any single muscle group or joint and thus increase the likelihood of completing that exercise, pain free and efficiently. Bingo. Load sharing.
The antagonist exercise to load sharing, in that it is actually the exact opposite. In isolation, we want to completely isolate one single target muscle group. Why? Well, theory tells us that promoting a targeted focus on a single group of muscles (i.e. pectoral major muscle in chest flys) concentrates that work load in that specific region. In doing so, what I have seen is a stronger recruitment or breakdown of muscle fibres, thus leading to quicker muscle development. Of course there’s exceptions to the rule, but this is a general consensus and the reason why isolation exercise is so popular amongst the bodybuilding world of fitness.
Over the years I have seen a few great differences between the two countering styles from a practical standpoint. While neither style is right or wrong in theory and practicality, I’ve seen that there’s a right and wrong time to use either and that’s simply based around each individual and what they’re looking for out of exercise. This is why I caution you to do your research when you’re getting back into an exercise regime.
Here’s the thing with isolation. I would argue it is more of an advanced or specialization style of training, even though it doesn’t in theory utilize more engagement. When you isolate an exercise, let’s use the back step lunge for example, you tend to cause all of the load of that exercise on one joint, in this case, the knee joint. Why? Well, generally trainers that coach a compound movement in the isolation style will coach you to force your trunk straight up from the hip, causing all of the force to be exerted through the quadricep in the front leg of the lunge. Over time, what I’ve seen in both myself and in clients is that this exercise promotes more direct strain on that knee joint because of that high load always forcing itself on that specific joint. It has no where else to go, so we tend to see over use injury as a result. things like IT band syndrome and quad tendon inflammation or (the highly over diagnosed) patellofemoral syndrome.
In my opinion, load sharing is a much safer, functional and therefore more enjoyable form of exercise when it comes to fitness, which as I said earlier – 90% of the people are looking for in regards to lifestyle goals. Take that same back step lunge, and now instead up keeping your trunk completely upright, hinge slightly, only about 15 degree forward while still maintaining a flat back (or “neutral spine”). This simple action puts your hips in just enough flexion to take a share of the load from the knee joint and help you to get up more efficiently with all of your body. This action alone can help prevent overuse injuries of the knee, as you’re not relying on just the one joint to take that whole load all of the time. Overuse injuries are something I see very common with folks coming to me for assistance in getting their lifestyle back on track and let’s face it, if exercise causes pain, you’re likely not going to stick with it.
That being said, I would suggest really doing your research when you’re pulling exercise programs off of the bodybuilding.com’s or womenshealth.com’s of the internet. Because, oftentimes those writers gear the free exercise programming to the aesthetically pleasing goals of what everyone wants – “get a 6 pack in 6 weeks” or “9 ways to bigger biceps”. Unfortunately, there’s no shortcut to any fitness goals and if you try to cut corners and skip the crucial foundational stage of exercise – your tagline will read something like “6 weeks and $600 for a lot of lower back pain and a physiotherapy bill” or “9 reasons I strained my rotator cuff and now have tennis elbow”.
It’s simple folks, you can’t shortcut. I truly believe that professional assistance is crucial in order to start a lifestyle overhaul and continue to make ground on your goals, be it physically, personally or otherwise.
Hopefully my explanation about the difference between a load sharing exercise and isolation theory allows you at least think about your ego and how much more important it is than effective exercise and injury prevention. There’s a time and place for both styles and I hope this article helps you to decipher where you’re at in regards to using both.
Thanks for reading!
You don’t have to be a rock star to start, but you have to start in order to become a rock star.