MOBILITY-Why It Matters
With every single workout we prepare our body for performance. We include some MOBILITY work, where we focus on improving our range-of-motion in the joint(s) specific to our upcoming movements. A very real example: If we're going to work overhead, we open up our shoulders, and we also work on our thoracic spine (upper and middle back), because the thoracic spine is usually a major limiter to our shoulder range of motion. When we prepare our t-spine and shoulders appropriately, then we don't have to overextend our lumbar spines (low back) to compensate to get our arms directly overhead. Why don't we want lumbar over-extension? Because 1) it leads to injury, 2) you aren't working your core (think abdominals) like you should & want to work them, and 3) your performance suffers--i.e. you aren't lifting as much weight as you could, or you're not lifting for as many repetitions as you could.
The hips, ankles, elbows, shoulder rotators can all be mobilized as well, and should be, dependent upon what movements are required that day. MOBILITY work is needed to improve our specific joint range of motion, and then we need to use our bodies in that new-found range of motion, so the nervous system recognizes that we are indeed capable of performing in the range of motion. This becomes even more important as we age, and our muscles and connective tissues naturally begin to shorten. We need to keep the joints healthy, and working properly, for a lifetime.
Then the focus shifts to MOVEMENT. We need to be more aware of how our body is moving, of what motion we want our body-parts to make. We do this to move better, safer, more efficiently, & more EFFECTIVELY. We need to improve how we are able to engage our abs, or have all of our shoulder musculature active, or engage our posterior chains, etc. in order to be working safely and optimally--in order to produce BETTER RESULTS. That's why we're exercising isn't it? Because we want RESULTS!
So why should you be working on MOBILITY? The only reason would be for BETTER RESULTS, by improving performance, and preventing injury. If those aren't important to you, then by all means skip the MOBILITY and just jump right in--I'm sure your body will forgive you, but you will NOT get as good of RESULTS.