Take It Easy: Too Much Exercise Frazzles the Vagus Nerve

Enhancing bodily fitness needs putting strain on your system for the duration of vigorous exercise sessions. But the quest for peak effectiveness often backfires—the psychophysiological distress brought on by abnormal physical exercise isn’t good for you. Getting a “Goldilocks zone” exactly where your every day workouts place enough strain on your body to strengthen exercise with out overdoing it can be difficult.

Chris Bergland ending a Triple Ironman in the early 2000s.

Source: Chris Bergland

For instance, when I was seeking to get in condition for extreme functions like the Triple Ironman (7.2-mile swim, 336-mile bicycle, 78.6-mile run), the chance of damage and burnout was incredibly superior. Monitoring fluctuations in my coronary heart rate variability (HRV) was a way to make positive I was not overtraining.

The vagus nerve’s capacity to counteract the sympathetic anxious system’s struggle-or-flight tension reaction is mirrored by bigger HRV.

In addition to preserving tabs on how my anxious process responded to the previous day’s strain load by employing HRV, I also held tabs on working day-to-day mood variations. By means of trial and mistake, it grew to become obvious that if I was seriously cranky and in a foul mood the early morning following an powerful teaching session, it meant I was on the verge of acquiring burned out from overtraining and necessary to get it easy for a day or two.

As a retired serious-length athlete, I know from lived practical experience that performing way too significantly training can be damaging to your psychological and bodily well-remaining. Overtraining is each stamina athlete’s Achilles heel. It can be so effortless for one’s passion for sports activities and opposition to develop into physical exercise fanaticism, which usually prospects to injuries or too much to handle psychological distress.

Overtraining, Minimal HRV, and Unfavorable Moods Go Hand in Hand

New investigation (Alfonso and Capdevila, 2022) from the Universitat Autònoma de Barcelona (UAB) in Spain presents us fresh new insights into the backlink between HRV, overtraining, and temper states. Their peer-reviewed conclusions ended up printed on March 30 in the PeerJ journal.

Carla Alfonso and Lluis Capdevila of UAB’s Laboratory of Activity Psychology identified that if a bicycle work out was really rigorous and set too considerably tension on a cyclist’s body, HRV plummeted the following morning. Alfonso and Capdevila also learned that HRV concentrations correlated with cyclists’ moods. Low HRV was correlated with negative temper states increased HRV was involved with improved mood states.

“The goal of the analysis was to explore the relation among 3 elements: teaching, heart price variability, and temper,” Alfonso mentioned in a information launch. “With this study, we aimed to know when an athlete ought to rest, simply because their method is saturated, and when an athlete can teach, with far more or a lot less depth, mainly because their system is prepared to assimilate the teaching load.”

The most important takeaway from this pilot review is that HRV and mood states seem to increase and drop in tandem. For example, if a “weekend warrior” overdoes it on Sunday, odds are that they’ll be cranky or in a bad temper Monday morning. Destructive temper states the working day soon after placing as well a lot stress on your system by overtraining correlate with lower HRV.

This illustration reveals the human mind and “wandering” vagus nerve. In the 1920s, a German-born researcher named Otto Loewi uncovered that electrically stimulating the vagus nerve introduced a parasympathetic substance that slows heartbeats and calms the anxious program. Now, we refer to this vagus substance as acetylcholine. Loewi known as it “vagusstoff.”

Resource: Axel_Kock/Shutterstock

Coronary heart Price Variability Reflects the Vagus Nerve’s Reaction to Strain

The vagus nerve secretes an inhibitory compound immediately onto the coronary heart, slowing it down. Heart charge variability steps how correctly vagus nerve exercise is developing nutritious fluctuations in between heartbeats. Better HRV indicates that the entire body has a robust skill to tolerate and get well from anxiety. Conversely, lessen HRV means that the vagus nerve is “frazzled” and is not proficiently inhibiting the sympathetic anxious system’s fight-or-flight response, which revs up heartbeats and reflects a reduce tension tolerance.

Otto Loewi won a Nobel Prize in 1936 for his discovery that stimulating the vagus nerve releases an inhibitory material that slows heartbeats and calms the anxious technique.

In the 1970s, my neurosurgeon father taught me about Loewi’s vagus nerve exploration in the context of maintaining grace less than force. My father realized that “vagusstoff” was unveiled for the duration of the exhalation section of the respiration cycle. So, he used respiration routines to continue to be serene all through brain surgery and on the tennis court. (See “How ‘Vagusstoff’ (Vagus Nerve Compound) Calms Us Down.”)

When I was a younger tennis participant, Father coached me to choose a swift inhalation by means of my nose followed by a lengthy, sluggish exhalation by means of pursed lips to relaxed my nerves prior to just about every provide. A the latest examine found that one particular 5-moment session of deep, slow-breathing exercise (four seconds in, 6 seconds out) boosts vagal tone and cuts down anxiety. Individually, I like an inhale-exhale ratio of four-second inhalations followed by eight-2nd exhalations.

On the basis of evidence-dependent investigate and lived practical experience, I know that longer exhalations are an simple way to hack your vagus nerve by triggering the release of vagusstoff. But, I also fully grasp that the calming impact of these respiration workouts tends to be short-lived.

When the sympathetic anxious technique is overstimulated by far too a great deal exercise, diaphragmatic respiratory is just a bandage that presents you short-term reduction. Rest is the most effective solution for offering your vagus nerve and parasympathetic technique a probability to bounce back.

To Sum Up: Too much Training Decreases Vagus Nerve Tone as Indexed by Small HRV

HRV is an indispensable instrument for holding tabs on how your vagus nerve responds to workout-induced pressure and making certain that you do not overtrain. Lower HRV implies that the struggle-or-flight mechanisms of your sympathetic nervous program are in hyperdrive and that vagal tone is weak. Conversely, larger HRV exhibits that vagus nerve activity is strong and that your parasympathetic anxious system is dealing with anxiety properly.

The most recent research (2022) on HRV and overtraining reaffirms that lower HRV is a warning signal that your vagus nerve may possibly be “frazzled” from way too considerably psychophysiological distress. If you will not have obtain to an HRV observe, experiencing negative moods the day after exercising vigorously may possibly be a indicator that you ought to get it quick for the subsequent 24 several hours and give your technique time to recuperate.