The sympathetic nervous system (SNS) is known to be in charge of our fight, flight and freeze responses, while the parasympathetic nervous system (PNS) governs rest, digest and repair. The SNS and PNS are part of our autonomic nervous system, which we do not have conscious control over. Despite this, our thoughts and actions do influence which part of the nervous system is dominant at any given time.
| Function | SNS | PNS |
| Fuel | Glucose | Fat |
| Breathing | Fast and shallow | Slow and deep |
| Blood pressure | High | Low |
| Heart rate | High | Low |
| Muscles | Contracted | Relaxed |
| Digestion | Poor | Good |
When the SNS is dominant, glucose from carbohydrates is our primary fuel source. When our glycogen (stored glucose) is depleted, amino acids from protein are converted into glucose, as fat cannot be converted into glucose. However, when this fuel source runs out, amino acids from protein are converted into glucose for energy by a process called gluconeogenesis (converting a non-glucose substance into glucose during times of need). The problem here is that if we do not have a surplus of amino acids from our diet to convert into glucose, our body will resort to the important amino acids that were going to be used to repair our muscle tissue, regenerate our cells, and grow our skin, hair and nails. Our muscle tissue may be broken down to produce glucose for energy. This is counter-intuitive to fat burning as our muscle mass is a significant user of calories. When the PNS is dominant, fat is our primary fuel source. When dietary fat has been utilised, our stored body fat is used as fuel. To clarify this, the more relaxed you are, the more fat you burn. The more stressed you are, the less fat you burn.
Tips to activate you parasympathetic nervous system and fat burning potential:
Diaphragmatic breathing is one of the most simple and effective ways of calming down the nervous system. When we are stressed and rushing around we breathe shallowly into our lungs, rather than deeply into our belly. If you need a reminder to breathe diaphragmatically, use the clock as your reminder. Place your hands on your belly, on the hour, every hour. Breathe slowly and deeply for 10 breaths with your eyes closed. If you need a reminder, set an alarm on your phone until it becomes a habit. Check out my Stress Less Tonic.
Caffeine increases adrenaline and promotes SNS activity. Adrenaline is the stress hormones that surges through our body in preparation to fight, flight and freeze. Reduce caffeine by substituting it with dandelion coffee, chai or herbal tea as your morning ritual.
The type of movement you do influences whether exercise has a stressful or relaxing effect on your body. Chronic cardio and long workouts have a negative effect on the nervous system and fat burning. When adrenaline is increased for a prolonged period of time, it is stressful on the body and the SNS remains dominant for longer after exercise. Shorter, more intense workouts are more supportive for the nervous system. This is because adrenaline is only increased for a short amount of time. Gentle exercises like walking, yoga and pilates supports the PNS.
Sleep is a time when SNS activity is non-existent. Ensure that you get adequate sleep (around 8 hours) to maximise PNS activity. Quality rivals quantity, read about how to achieve good quality sleep here. Often when we are sleep deprived and lacking energy, we reach for caffeine to give us a quick energy boost. Poor sleep and caffeine can be a vicious cycle. Check out my Sleep Deep Tonic.
Relax and slow down. We feel stressed when our life is passing before our eyes and we do not have time to appreciate the little things. Live in the moment and be grateful for everything. Practicing gratitude supports the PNS. Have a break from technology and social media to let your mind wander. Research shows that technology and social media increases our stress hormones. Check out my Chillax (Chill Out & Relax) Tonic.
Do what you love. It is impossible to be stressed when you do what you love. Write a list of everything you love to do and schedule it in your diary. Daily, weekly, monthly or even yearly depending on what it is. If you do not schedule it in, it probably will not happen.
Herbal Medicine can calm the nervous system and support the PNS. Consult with me to determine which herbs are indicated in your individual case.
Check out my blog Enhance Your Resilience to Stress
