Your Body is Adapting
Change can be hard to see. It happens to you over the course of days, months, and years. Often you don’t notice the difference until you take a second to stop and reflect.
Maybe you take out the old photo album or run into a friend you haven’t seen in many years. Suddenly, you notice that, in some ways, you’re a different person now than you were many years ago. Maybe you’ve gained a few pounds, lost a few hairs, and developed some wrinkles.
You shouldn’t be shocked by this, as you know that the human body adapts and changes over the course of time. However, you may have never stopped to think about why this happens.
But, if you want to have a hand in shaping this change, then understanding why and how your body adapts to the environment and the stressors around it is critical. This allows you to take control of how your body adapts by being conscious of your environment and the stress you place on your body.
As a former Exercise Science student and now a trainer, I am constantly amazed at the wonder of the human body. To think that what begins as a single cell can multiply into 10-100 trillion cells, which somehow work together in many different forms and functions to produce an adult human, is mind-boggling. This often leaves me thinking of these verses of Scripture:
“For you formed my inward parts; you knitted me together in my mother’s womb. I praise you, for I am fearfully and wonderfully made. Wonderful are your works; my soul knows it very well.” – Psalm 139:13-14 NIV
While embryology and the study of human development through childhood is an amazing thing, as a trainer, I am more in tune with the amazing way that the human body adapts to the specific stress that we place upon it.
In fact, the body follows a specific principle of adaptation known as the SAID (Specific Adaptation to Imposed Demand) principle. This principle is of great importance when it comes to exercise and training the body. It means that we can create an environment and demands on the body that will cause it to adapt and get stronger. And we can do this in a very specific way.
If we want to make someone stronger, we can do that. If we want to make someone faster or more powerful, we can do that. If we want to improve someone’s balance and stability, we can do that. If we want to increase someone’s muscle and reduce their fat, we can do that. Etc.
Trainers, physical therapists, chiropractors, massage therapists, and other health professionals rely on this principle to impose the exact stress they want in order to get the specific adaptation that is desired.
Athletes and those training for high level competition rely on this to make their body into a lean, mean, athletic machine. What they’re training for may require extreme strength, power, speed, or all three. But whatever they need, it is possible to train the body for that purpose.
I find this principle to be one of the most exciting things about the human body. It means that we have the ability to shape our bodies, to a degree, by the stress that we impose upon them. You just have to know how to impose that stress properly.
However, the flip side of this adaptation is not as exciting. Your body doesn’t just adapt in positive ways when you exercise, eat healthy, and train it in a smart way. It also adapts in negative ways if you choose to abuse your body.
The fact that this principle of adaptation goes both ways is because your body will adapt to WHATEVER stress you put it under. If you thought that sitting on the couch watching TV all day wasn’t stressful, think again.
If you choose to never move your body, or put positive stress on it from physical labor or exercise, it will adapt to never being stressed enough. If you sit all day, you are sending your body the signal that it doesn’t need to be strong. It doesn’t need to be in good cardiovascular shape. It doesn’t need to be flexible or move freely.
All it needs to do is sit. And it can get really good at sitting.
Unfortunately, this kind of inactivity is becoming dominant in today’s culture, as we move further away from manual labor and into the age of technology.
We have an idea of what this negative adaptation looks like on the outside. But what is even more important for health is what this adaptation looks like on the inside. Let’s take a look.
Muscles are amazing things that can adapt very quickly to stress. For a novice exerciser, significant increases in muscular strength can occur within 48 hours of a workout. That means if they lift 50 pounds in the gym on Monday, by Wednesday they’ve already adapted and can now lift 55 pounds. This is something they could not have done just two days before!
But muscles need to be stressed adequately and consistently or they will lose strength and mass very quickly. Continuing to challenge your muscles will lead to continued strength increases, while remaining sedentary will decrease muscle strength and mass.
The heart is also a muscle. Many times, it gets separated from the rest of the muscular system, but it will also atrophy if it is not challenged enough. This is significant because the heart drives blood flow through the whole circulatory system.
If the heart is not strong enough to pump all the blood out of it and into the blood vessels each beat, then the body is at risk of not getting enough oxygen and nutrients to all of the tissues. This can lead to excessive fatigue and exhaustion during physical activity.
But that isn’t the only problem with a weak heart. If the heart is too weak, blood can begin to pool in the heart as well as in the circulatory system. It just can’t get pushed all the way through. This can lead to bad things like fluid pooling in the extremities and Congestive Heart Failure.
Fortunately, cardiovascular conditioning through exercise can help remedy this problem!
If you know anyone with Osteopenia or Osteoporosis, then you know that bones can lose mass too. In fact, astronauts who remain outside of the earth’s gravitational effect for long enough may need to be helped off their ship in a wheel chair because their bones will have lost a significant amount of density (One more reason to never be an astronaut!).
When most people think about exercise, they only think about decreasing fat, increasing muscle, and increasing conditioning. They often don’t realize that exercise also promotes bone health.
Bones are constantly remodeling themselves via a combination of old bone being removed and new bone being added. That’s why bones will heal even stronger after they are broken . The one rule is that new bone must be added along the lines of stress imposed on it. But as NASA knows all too well, if there is no stress, there is no new bone added.
If you want healthy and strong bones, then regular exercise is a way to remodel the bones and make them stronger.
Posture is also an adaptation to stress. In this case it is sustained stress over a period of time. The tissues of the body will alter themselves over time based on chronic postures. The classic example of this is upper back rounding and forward head posture.
Don’t Be A Hunchback!
This is an adaptation to living in this position for many months or years. In most adults, the head weighs a minimum of 1/7 your total bodyweight. That’s a lot of weight for the muscles in your neck and upper back to hold up.
If your muscles must work constantly to hold the head up when it is out of proper alignment, then you can develop painful symptoms in the neck and upper back like trigger points, Cervicogenic headaches (I just wanted to say that word because it sounds cool! Also, it means a headache that has its source in the neck or Cervical spine), and a constantly stiff and sore neck and upper back.
Most people are not born with this kind of posture. Rather, it occurs because we sit in front of computers, tablets, smartphones, books, etc. for 10-12 hours per day . While a massage is very helpful in calming the symptoms, it does not deal with the source of the problem. Fortunately, this is also something that can be affected by changing your posture, and getting active!
As you can see, there are a lot of negative adaptations in the body because of inactivity. This is certainly not an exhaustive list, as increasing overall bodyweight and fat due to sedentary behavior also leads to all kinds of symptoms. But it gives you an idea of why your body literally NEEDS exercise and movement. It is made to endure and adapt in a positive way when good stress is placed upon it.
As a trainer, I view myself as a stress manager. Our bodies need stress, but not the bad kind. They need the good kind that comes from movement and exercise.
Your body is adapting, whether you know it or not. The only question is, what is it adapting to? Is it getting stronger and healthier, or is it becoming more deconditioned. You are the only one who can control which one it is. Only you can prevent muscle atrophy.