Chapter 8: Core and Balance Training Principles
Center of Gravity
Finding the Center of Gravity
You may have heard the term center of gravity in reference to balance and you might intuitively know that a toddler’s big head raises their center of gravity, which makes them less stable than adults. We already know that the force of gravity is what gives an object weight, but what is the center of gravity? Think about which body part you feel gravity pulling on. Do you feel it pulling on just your leg, or your arm, or what? Actually, the force of gravity acts on all of your mass in the same way, according to Newton’s Universal Law of Gravitation down to every single molecule and atom. If we break up your body into many many small chunks of equal mass we could calculate the tiny force of gravity on each one. If we add up all those tiny forces we get your total weight. If we average the locations of all those equal tiny forces, the resulting location would be the center of gravity. If we averaged the location of all the equal chunks of mass that would be the center of mass. Everyday objects, like humans, are small enough that gravity acts uniformly on all parts of the object and the center of gravity and the center of mass are essentially the same location. Check out the following video to learn how to experimentally find the center of gravity (mass) of an irregular object.
Reinforcement Exercises
Balance
Being out of balance means that your center of gravity is no longer above your support base (usually the space between your feet). When that happens you either fall down or take a step to widen your support base (regain your balance). Let’s examine why those are the only two options you have.
Video Resource
Freely rotating objects tend to rotate around their center of mass. The video link (youtu.be/DY3LYQv22qY) shows a neat demonstration of this phenomenon.
On the CDC Healthy Weight website we are reminded that permanent weight loss is a result of making changes to eating habits that become a long-term part of a healthier lifestyle. It is also reprinted below for your convenience.
Reflect, Replace & Reinforce: A process for improving your eating habits
Reflect:
Create a list of your eating habits. Keeping a food diary for a few days, in which you write down everything you eat and the time of day you ate it, will help you uncover your habits. For example, you might discover that you always seek a sweet snack to get you through the mid-afternoon energy slump. Use this diary to help. It's good to note how you were feeling when you decided to eat, especially if you were eating when not hungry. Were you tired? Stressed out?
Highlight the habits on your list that may be leading you to overeat. Common eating habits that can lead to weight gain are:
- Eating too fast
- Always cleaning your plate
- Eating when not hungry
- Eating while standing up (may lead
to eating mindlessly or too quickly) - Always eating dessert
- Skipping meals (or maybe just
breakfast)
Look at the unhealthy eating habits you have highlighted. Be sure you have identified all the triggers that cause you to engage in those habits. Identify a few you would like to work on improving first. Don't forget to pat yourself on the back for the things you are doing right. Maybe you almost always eat fruit for dessert, or you drink low-fat or fat-free milk. These are good habits! Recognizing your successes will help encourage you to make more changes.
Create a list of "cues." Review your food diary to become more aware of when and where you are "triggered" to eat for reasons other than hunger. Note how you are typically feeling at those times. Often an environmental "cue," or a particular emotional state, is what encourages eating for non-hunger reasons.
Common triggers for eating when not hungry are:
- Opening up the cabinet and seeing your favorite snack food.
- Sitting at home watching television.
- Before or after a stressful meeting or situation at work.
- Coming home after work and having no idea what's for dinner.
- Having someone offer you a dish they made "just for you!"
- Walking past a candy dish on the counter.
- Sitting in the break room beside the vending machine.
- Seeing a plate of doughnuts at the morning staff meeting.
- Swinging through your favorite drive-through every morning.
- Feeling bored or tired and thinking food might offer a pick-me-up.
Circle the "cues" on your list that you face on a daily or weekly basis. Going home for the Thanksgiving holiday may be a trigger for you to overeat, and eventually, you want to have a plan for as many eating cues as you can. But for now, focus on the ones you face more often.
Ask yourself these questions for each "cue" you have circled:
- Is there anything I can do to avoid the cue or situation? This option works best for cues that don't involve others. For example, could you choose a different route to work to avoid stopping at a fast food restaurant on the way? Is there another place in the break room where you can sit so you are not next to the vending machine?
- For things I cannot avoid, can I do something differently that would be healthier? Obviously, you cannot avoid all situations that trigger your unhealthy eating habits, like staff meetings at work. In these situations, evaluate your options. Could you suggest or bring healthier snacks or beverages? Could you offer to take notes to distract your attention? Could you sit farther away from the food so it won't be as easy to grab something? Could you plan ahead and eat a healthy snack before the meeting?
Replace:
- Replace unhealthy habits with new, healthy ones. For example, in reflecting upon your eating habits, you may realize that you eat too fast when you eat alone. So, make a commitment to share a lunch each week with a colleague, or have a neighbor over for dinner one night a week. Other strategies might include putting your fork down between bites or minimizing other distractions (i.e., watching the news during dinner) that might keep you from paying attention to how quickly—and how much—you are eating.
- Eat more slowly. If you eat too quickly, you may "clean your plate" instead of paying attention to whether your hunger is satisfied.
- Eat only when you are truly hungry instead of when you are tired, anxious, or feeling an emotion besides hunger. If you find yourself eating when you are experiencing an emotion besides hunger, such as boredom or anxiety, try to find a non-eating activity to do instead. You may find a quick walk or phone call with a friend helps you feel better.
- Plan meals ahead of time to ensure that you eat a healthy well-balanced meal
Reinforce:
- Reinforce your new, healthy habits and be patient with yourself. Habits take time to develop. It doesn't happen overnight. When you do find yourself engaging in an unhealthy habit, stop as quickly as possible and ask yourself: Why do I do this? When did I start doing this? What changes do I need to make?
Be careful not to berate yourself or think that one mistake "blows" a whole day's worth of healthy habits. You can do it! It just takes one day at a time!