Our physical, emotional, and cognitive aspects are interconnected and interdependent. This is the case whether we use a psychodynamic approach or a cognitive-behavioral psychological approach. If we are experiencing (noticing) dysfunction in one area, the whole system is actually affected. The good news about this is that by changing things in one aspect, we can affect other aspects as well.
This does not mean that we can simply “think away illness” or that if we can exercise “perfectly” (whatever that would be!) then our thoughts and feelings will just “snap out of it” into rationality and/or bliss. What it does mean, however, is that when we gradually move our habits towards health and balance in one aspect, the other aspects will also move more towards health and balance.
That means when behaviors become healthier, thoughts and feelings become healthier. When thoughts become healthier, feelings and behaviors become healthier. When feelings become healthier, behaviors and thoughts become healthier. A change in any one of them changes all of them!
When we consider the interconnected areas of behavior, cognition, and emotion, the most easily and directly influenced aspect is behavior. We can change what we do, which can help to change what we think and how we feel.
Remember, with any behavior change, the idea is not instant change, but rather successive approximation: doing things a bit more like the goal behavior, and then when that sticks, we do it a bit more like the goal behavior. Attempting drastic changes is less likely to create long-term change than creating and conditioning gradual habit change.
This really interesting clip discusses some ways in which developing–for example–a yoga practice can influence not only thoughts and feelings but also our bodies down to the cellular and chemical level:
Intersectional Life Counseling and Psychology, LLC 