Let’s learn how our bodies work. The body’s systems most directly affected by regular exercise are the skeletal, muscular, cardiovascular, respiratory, nervous, and endocrine systems.
We have already looked at the main functions of the skeletal, muscular, cardiovascular, and respiratory systems. Let’s now take a look at the last two, the nervous and endocrine systems.
The nervous system
The nervous system is made up of your brain and spinal cord (central nervous system) and the numerous nerves branching out from your spinal cord to the rest of the body (peripheral nervous system).
Electrical impulses within your nerve cells (or neurons) trigger the production of chemicals known as neurotransmitters, such as serotonin, which send all the vital messages between your central nervous system and everything else in your body, including your muscles, telling them what and when they need to do.
The nervous system has two parts:
- Sympathetic: “fight or flight”
This prepares your body for emergencies by rising your blood pressure, heart rate, and breathing rate, and sending blood to your muscles in readiness for action.
It’s dominant when you are very active and/or stressed.
- Parasympathetic: “rest and digest”
This restores your energy by keeping your blood pressure, heart rate, and breathing rate at a low level, and focusing on your body’s many crucial underlying functions, such as digestion.
It’s dominant when you are at rest or engaged in relaxing activities.
Over-stimulation of one system or the other can eventually lead to imbalance in the body. Nevertheless, regular exercise of the right kind can help to restore this balance—vigorous exercise such as intense biking or running workouts help to rev up your sympathetic nervous system, if required, while gentle activities such as slow walks and swims, and nourishing yoga sequences, help to activate the relaxation response of the parasympathetic system.
The endocrine system
The main responsibility of your endocrine system is to keep your body in balance (homeostasis). It does this by the release of hormones from various organs and tissues around the body that help to control, among other things, mood, energy, fertility, metabolism (which impacts weight control), and growth.
However, hormone levels can become out of balance for all sorts of reasons—such as during times of heightened stress or anxiety, and for women when it’s the “time of the month,” or if they’re going through menopause.
Fortunately, research suggests that regular exercise can help to balance hormones. Physical activity can, for instance, encourage the release of more endorphins, which reduce tension and anxiety, and help to stimulate a positive frame of mind.
Exercise can also help to balance levels of the sex hormones estrogen and testosterone, as well as those of growth hormone, which is especially useful for anybody over 40, since your natural levels of these hormones tend to decrease as you age.