Sympathetic Vs Parasympathetic: Why Every Athlete Needs to Understand the Difference

Expert Verified By: Andy Galpin, PhD and Dr. Mike T. Nelson

What if you could will yourself to absorb food better? OK, that sounds like magic, but — and we promise there’s science supporting this — in two minutes and without leaving your chair you can purposefully put your body into a state in which you do a better job of absorbing protein and other nutrients, recovering from exercise, regulating your mood, maintaining low blood pressure, and straight up improving longevity.

No, this isn’t another meditation article (here’s a very thorough one, though), we’re talking about how you can and should manipulate your own nervous system. It’s almost always sympathetic when it should be parasympathetic, meaning it’s in “fight or flight” mode when it should be in “rest and digest” mode.

This sounds very “woo woo” but these days we’re able to measure what direction your nervous system is leaning — this is real stuff — and too much time spent in a sympathetic state is super common has a lot of drawbacks, particularly for athletes.

Here are the surprisingly simple ways to nudge yourself back in the right direction and why you really, really should.

Editor’s note: The content on BarBend is meant to be informative in nature, but it should not be taken as medical advice. The opinions and articles on this site are not intended for use as diagnosis, prevention, and/or treatment of health problems. It’s always best to talk to a medical professional before undertaking any new diet or training regimen, especially if you have a preexisting condition.

Parasympathetic Vs Sympathetic Nervous System

Many of us think of “fight or flight,” often referred to in medical literature as a sympathetic state, as the sensation you only experience a few times in your life: a near death experience, fighting a bear, that kind of thing. But experts believe that most of us are in a milder version of that sympathetic state for the majority of our waking lives. We seldom really feel like it’s OK to relax.

Your autonomic nervous system is closely associated with the vagus nerve, the longest nerve in the brain, which snakes from the skull to the neck through the thorax and all the way to the belly. Its job is largely to supply motor parasympathetic fibers to practically every organ in the body, a process described as increasing vagal tone. The vagus nerve is responsible for tasks as diverse as heart rate, respiratory rate, perspiration, anxiety, helping move food through the digestive tract, and more.

This nerve could be doing more for you.

“Think of parasympathetic like the brakes on your car and sympathetic as the gas,” says Dr. Mike T. Nelson, CSCS, an adjunct professor at the Carrick Institute whose PhD focused on metabolic flexibility. “Pushing down on the brakes is increasing vagal tone. So it’s a sliding scale, you can be very sympathetic or somewhat sympathetic — but most people are sympathetic.”

Studies have suggested that low vagal tone (or a more sympathetic system) is associated with markers of inflammation, stress, and obesity, and a more parasympathetic system has been linked to everything from better learning ability to better insulin sensitivity.(1)(2)(3)(4) Going parasympathetic as soon as you can after a workout has been linked to better recovery and increasing vagal tone has even shown promise as a means for managing autism and neurodevelopmental disorders.(5)

Kebabs on a grill

Parasympathetic Innervation of Digestion

For athletes, it might have even more importance. Insufficient vagal tone has been associated with worsened reaction time and decision-making abilities among some athletes, and a ton of research has suggested that a parasympathetic nervous system does a significantly better job of secreting insulin, absorbing nutrients and burning calories.(6)(7)(8)(9) One study published in Nutrition noted(10),

The parasympathetic system would appear to influence the thermic response to meal ingestion by modulating obligatory thermogenesis, i.e., the rate at which nutrients are digested, absorbed, and processed by the various tissues and organs of the body.

One study from the 80s even found that being very sympathetic results in thermogenesis decreasing by up to 60 percent and while that’s almost certainly an overstatement, this is still a serious factor in your nutrition.(11) If your body is on alert for danger, it isn’t going to fully focus on perfectly digesting or recovering. (“Food? Just put it over there, I’m trying to look out for wolves.”) That’s why a lot of elite bodybuilders, like Ben Pakulski, meditate for a couple of minutes before eating: it’s one way of putting your body into a more parasympathetic state.

Sympathetic vs Parasympathetic for Athletes

Wait a minute, shouldn’t athletes try to be more “fight or flight”?

Sure, when it’s time to train. But you’re staying fight or flight all day.

“Deliberately combining your autonomic nervous system with your task is sometimes called autonomic pairing,” says Nelson. “If I’m going to eat I know I want to be in more of a ‘rest and digest’ state. Just like if you want to lift a maximal load, you want to become more sympathetic to enhance that process.”

The good news is that despite the apparent fact that athletes need to be sympathetic more often than the couch bound, studies suggest that they’re better at maintaining a balance between those states. (Yogis are better than runners who are better than sedentary people, concluded one not-all-that surprising 2015 study.(12))

Practice at getting psyched up makes it a little more deliberate for the body, plus you already know that exercise is great for managing stress and blood pressure, which can be closely tied to vagal tone. Purposely and strategically stressing your system is better for your body than just kind of being in a slightly agitated and stressed state all of the time, which is the case for most of the population, physiologically speaking.

What athletes should aim for is an ability to get sympathetic and then switch back to parasympathetic at will.

“For me, that’s the holy grail. To be able to transition in and out of those states as fast as possible,” says Nelson. “If you’re trying to lift a max load at the gym you should be very sympathetic but at the end of training or even between sets, you should try to get as parasympathetic as possible.”

While we’re trying to use a lot of scientific language here, it’s true that we’re talking about different degrees of getting psyched up. We don’t want to say absolutely everyone should get as psyched as possible for all of their work sets, but learning to crank that system up can definitely be a useful skill, particularly when you need a ton of raw power and strength.

“Even in sports like basketball or American football, athletes will be very parasympathetic and relaxed off the field before switching it back on when it’s time to play,” says Nelson. “You don’t want to never be sympathetic, you just want that response to be appropriately matched to what you’re doing.”

Parasympathetic Nervous System Activation

Most people are clueless as to how to downregulate their system, especially since most of us have been just a little bit “fight or flight” for most of our adult lives. Here are a few tips for getting parasympathetic.

1. Breathe deeply

Insanely simple, super effective, spending a few minutes just focusing on nothing other than taking deep, full belly breaths allows for improved oxygen transport, lowers blood pressure, and stimulates the vagus nerve, moving your dial from sympathetic toward parasympathetic.

You can also try counting your breaths while doing this, which is why you’re asked to slowly count backwards when you’re going under anesthesia at the dentist. It helps relax the system because everything you’re focusing on (numbers and breathing) is super predictable. Your mind doesn’t expect anything unusual to happen when you’re navigating the numbers from 1 to 10, since those numbers are always the same.

2. Meditate

This is cheating, because we really just recommended meditating — focusing on and counting your breaths is considered meditation. It doesn’t have to be any more complicated than that. Ever tried closing your eyes and counting to ten when you were angry? Calms you down, right? That’s meditation. (See, it’s not that weird.) Other kinds of meditating, like reciting a mantra or reciting the Catholic rosary have also been shown to affect your heart rate variability, which is very closely tied to your vagal tone.(13)

[Seriously, read this article about monitoring your heart rate variability. Do this right, and you’ll always know which autonomic nervous state you’re in.]

3. Try a sensory deprivation chamber

Zero sensory input is a pretty great way to convince the brain that it doesn’t have to be on alert for anything. Joe Rogan once called isolation tanks, “One of the greatest tools ever for exploring, thinking, exploring the way you think, and sort of making an audit of all your own personal thoughts and ideas.”

“I have clients go into a sensory deprivation chamber to remove as much stimulus as possible and get as quiet as you can,” says Nelson. “Once you get pretty good at that, you get a better idea of when you’re sympathetic and when you aren’t.”

4. Train awareness of your sympathetic states

Following on from that point, you can get better at moving into parasympathetic states by paying close attention to your sympathetic states.

“I’ll have clients do a 5×5 deadlift while wearing a heart rate strap, then I’ll say that their next set doesn’t start until their heart rate is at 80 beats per minute,” says Nelson. “I don’t care what you do, just get your heart rate back down.”

This is an open ended external cue: you figure out how to get your heart rate to 80, which is super low by exercise standards. Maybe you’ll look at your breathing, or just close your eyes and focus on relaxing, but you’ll figure out how to get down there. And the more you do it the quicker you’ll be able to get there. That’s good training.

5. Eat your minerals

Good intakes of zinc and magnesium have been linked to healthy vagal function and an autonomic nervous system that works better. They’re found in meat and leafy greens. Eat lots of these.

6. Manage your stimulants

Caffeine and other stimulants are pretty strongly linked to making you more jacked up, energetic, and nervous — more sympathetic. If you feel like you’re too “on edge,” eliminating or reducing your intake can go a long way to making your system calmer and more relaxed.

7. Massage and foam rolling

You know how everyone feels super relaxed after a massage and kind of relaxed after foam rolling? That’s because they both stimulate the vagus nerve. Massages are better (they just are) but both can be helpful for going parasympathetic so long as there’s a good amount of pressure being put on the skin.(14) Don’t ignore that stuff. Your fascia will thank you.

[Interested in picking up a foam roller? Check out our list of the best foam rollers on the market!]

7. Yoga

As previously mentioned, yogis are more parasympathetic than runners and sedentary people. Pro tip: follow the teacher’s instructions on breathing. Pay attention to your movements and your breath and body positioning instead of running through the day’s events in your mind and being distracted.

A lot of these are just different ways to turning off the critical thinking part of your brain, the part that’s constantly thinking about what you did yesterday and what you’re doing tomorrow, keeping you in a state of mild (or not so mild) anxiety and keeping the body on a low (or not so low) level of alertness.

Winding Down

We tried to keep this from being another “live in the moment, man,” article because unlike some discussions about relaxation (man), the autonomic nervous system is real and observable. Your vagal tone is observable. It’s not about chakras or auras, it’s about the activity of a nerve that runs from the brain to the belly. We know what it does — it tells your body it’s okay to rest and digest — and we know how to stimulate it.

Learn to activate your sympathetic nervous system and your lifts will be heavy and your workouts intense. Learn to activate your parasympathetic system and you’ll keep inflammation and stress low and your nutrient absorption and recovery optimal.

Become a renaissance man or woman of your nervous system. Have it both ways. Run your show.

Featured image via @eccentric_beast on Instagram.

Editor’s note: This article is an op-ed. The views expressed herein and in the video are the author’s and don’t necessarily reflect the views of BarBend. Claims, assertions, opinions, and quotes have been sourced exclusively by the author.


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