By Mackenzie Levin
Beyond the Physical: Recovery and the Parasympathetic Nervous System
Most of the research on recovery methods after bouts of exercise has focused on the physiological and physical responses to the stimulus imposed. Controlling the perception of fatigue is a major concern in many studies. Other effects that training has on bodily functions are largely forgotten. The parasympathetic nervous system plays a significant role in recovery. The perception of fatigue in athletes is often overlooked while attempting to manage an athlete’s plan of recuperation.
We’ll explain the various roles the parasympathetic nervous system (PNS) plays in exercise recovery. Methods of managing fatigue from overuse of the parasympathetic are explained including listening to music and utilizing breathwork and breath pacing.
The Autonomic Nervous System: Sympathetic vs. Parasympathetic
The Autonomic Nervous System (ANS) is comprised of both the sympathetic and parasympathetic systems. The purpose of the ANS is to regulate bodily processes. The sympathetic nervous system prepares the body in times of physical stress through a response commonly known as “fight or flight.” The heart rate elevates, pupils dilate, and blood pressure rises as the Sympathetic Nervous System (SNS) is mobilized.
The role of the parasympathetic nervous system is to reverse the effects the SNS implements. The phrase “rest and digest” is the most common term used to describe the effects of the parasympathetic nervous system. The PNS slows breathing and heart rate and stimulates hunger. The longer we stay in a parasympathetic state, the more time for recovery of the autonomic nervous system after intense training.
Parasympathetic Reactivation After Exercise
In exercise, the parasympathetic nervous system is activated after exercise bouts to begin the recovery process. Different types of exercise, specifically resistance training, can elicit a different type of response by the parasympathetic nervous system.
According to a 2020 study, performing repetitions to muscle failure “induces a more significant reduction of the parasympathetic nerve activity and higher internal training load.” In addition, inter-repetition rest “induced less psychophysiological stress.” This study suggested that various types of training can have different effects on the reactivation of the parasympathetic nervous system.
Measuring Recovery with Heart Rate Variability (HRV)
Heart rate variability (HRV) is a fluctuation of the length of heartbeat intervals. It is used as a means of measuring parasympathetic nervous system activity and is, therefore, a tool used to measure recovery in athletes.
A 2018 study found that “the most frequently reported factor associated with variation in HRV variables was low parasympathetic activity.” In training, athletes can measure heart rate variability as a means of understanding their relative state of fatigue. They can measure the amount of time between heartbeats and compare the time between each beat.
Low HRV is an indicator of possible impaired ANS function. Low HRV can be the result of overtraining when an athlete does not allow sufficient time for recovery before the next bout of exercise. In the studies referenced in this paper, heart rate variability is the method used to measure parasympathetic nervous system activation.
Parasympathetic Care and Reactivation
Many studies have shown the connection between proper care of the parasympathetic nervous system and the ability for the athlete to recover from training. “Parasympathetic nervous system care” can be defined as properly transitioning the body from being in a sympathetic state to a parasympathetic, or homeostatic state. This transition is seen when training is completed by an athlete, and the body reverses the effects of the sympathetic nervous system. This process is also known as “parasympathetic reactivation.”
Techniques for Parasympathetic Reactivation
Music and Recovery
There may be a few methods that can specifically be used for parasympathetic reactivation. In a 2021 study, it was shown that music can be used to change physiological responses in sedentary individuals. Music inhibited the activity of the autonomic sympathetic nerve and enhanced activity of the parasympathetic nerve. This was shown by the HRV in participants, which was measured by the time at which beats per minute decreased.
This information can be used and applied to the cool down phase of training. If music is played during the time that athletes take to cool down, the transition from a sympathetic to parasympathetic state may be expedited.
Breathwork and Breath Pacing
Another method to enhance parasympathetic reactivation is breathwork. A 2018 study demonstrated that repeated muscle contractions paired with paced breathing had a 150% higher parasympathetic activation than a control group. This showed that breathwork can play a role in the reactivation of the parasympathetic nervous system.
Breath work and pacing of the breath can be used after a training session to shift the body from the aroused sympathetic state. The practice of manually slowing down the breath mimics the functions of the parasympathetic nervous system. This will, in turn, slow down the heart rate, lower blood pressure, and reverse any other effects of the sympathetic nervous system.
This technique is already being used in exercise classes such as yoga, Tai Chi, and Qigong. These techniques have been used for many years to achieve a state of serenity and to help the body move through therapeutic movements.
Conclusion: Practical Applications for Athletes
There have been many studies on how to help athletes recover faster and more effectively. Although there is more research to be done on the exact mechanisms of recovery, there are known techniques to enhance the process of recovery.
Heart rate variability is used frequently in studies about athlete fatigue. There are ways to impact heart rate and heart rate variability, which in turn can impact the parasympathetic nervous system. Listening to slow-paced music can be an effective way to induce parasympathetic reactivation by slowing the heart rate and optimizing the heart rate variability for better recovery. Breathwork can also help slow the heart rate and simulate the process of parasympathetic activation.
These techniques can be used to improve an athlete’s quality of recovery, as well as enhance the process. Athletes could incorporate these practices into their daily routine to see recovery improve and feelings of fatigue decrease.
References
Chin, M. (2018). Understanding mind–body disciplines: A pilot study of paced breathing and dynamic muscle contraction on autonomic nervous system reactivity.
Stress and Health: Journal of the International Society for the Investigation of Stress. (35)4, 542-548.
Kassiano, W., Costa, B., Lima-Junior, D., Gantois, P., Fonseca, F., Costa, M., Fortes, L. (2020). Parasympathetic Nervous Activity Responses to Different Resistance Training Systems. International Sports Medicine Journal. (42)1, 82-89.
Kim, H., Cheon, E., Bai, D., Lee, Y., Koo, B. Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature. Korean Neuropsychiatric Association. (15)3, 235-245.
Wu, M., and Chang, T. (2021). Evaluation of Effect of Music on Human Nervous System by Heart Rate Variability Analysis Using ECG Sensor. European Heart Journal, 33(2), 739-753.
