Since fitness came onto the scene as one of the best ways to maintain your health, the body part approach has been the primary go-to for most participants. Most of us have heard (if not practiced) some sort of muscle split throughout the week (for example: back and biceps one day, chest and triceps the next day, and legs and abs the next). This is for good reason because it gives us proper time to recover, it's easy to understand and organize.
The problem is that little of what we do in everyday life is akin to the way we workout. Seriously, how many pull ups do you do per day (outside of exercising)? That being said, you use your back muscles constantly throughout the day, so the exercise definitely serves it's purpose, in a basic-needs kind of way. Although, if you are designing/following a more sophisticated and progressive training regiment, then you need to work in multiple planes of motion to strengthen...well, everything.
First off let's define the 3 planes of motion:
forward and backward
side to side
Most common exercises occur in the sagittal plane (forward/backward), while frontal and transverse movements are often overlooked. This can lead to imbalances in our training and ultimately our bodies. Injury prevention aside, incorporating multi plane movements into our workouts have numerous benefits including:
1. BALANCE - Balance is not just limited to our ability to maintain equilibrium, it also refers to our ability to maintain even weight distribution within that body part. That's why in Yoga you may hear them say "spread your toes" when standing, usually on one leg. This helps us maintain muscle synchronicity without overworking a specific area. By working in multiple planes, we can honestly attempt to master our balance.
2. AGILITY - In sports, agility refers to one's ability to move quickly and easily. Specifically, when we stop moving one direction and start moving in another direction. We obviously would lose count of the times that happens per day, so it's necessity needs no convincing.
3. ADAPTABILITY - When we do new things, take new routes and change up habits, our brain grows more neurons and creates new pathways. Multi plane training helps us do something similar because by varying up our movements, we are improving our body's ability to adapt to different environments.
4. TENDON & LIGAMENT STRENGTH - Use it or lose it. Most of us have sedentary jobs and know sitting puts further strain on our tendons and ligaments. These areas are also common centers for injury, and can take longer to heal. Make them feel important by cautiously and progressively strengthening them in all 3 planes.
5. SPORTS PERFORMANCE - (Almost) every sport requires us to move in every which direction, so training with just bench press, squats and curls (all sagittal movements) won't cut it.
TIP: Never be too proud to regress an exercise until you feel you can maintain perfect form. Once perfect form can be consistently maintained, you can progress to the next stage of the movement. If proper form cannot be maintained, look at where the problem area is. Performing corrective exercise (i.e. stretch, foam roll and activate) on the problem area can help expedite your advancement to the next stage of the movement. Check yourself before you injure yourself.