Strength coaches often drop cryptic references that pay homage to the power of the nervous system:

"If your performance starts to improve after set 7 or 8, that's your nervous system getting excited," or "Too much low-rep work can fatigue the nervous system," or my personal favorite, "While you might feel physically recovered and ready to train, your nervous system is actually a mangled wreck hooked up to an IV in a hospital bed surrounded by a team of concerned-looking physicians and a defibrillator."

As a young trainee, the nervous system seemed like a mysterious, powerful yet delicate tool that only true strength training savants could fully control. I realized that joining the ranks of the lifting elite required making my nervous system my willing servant.

Unfortunately, in my human physiology course, the nervous system confused the shit out of me. Between the synapses, calcium ions, nodes of ranvier, glial cells, and acetylcholine, it wasn't anything I'd expected.

I was lost between theory, practicality, and applicability. So I sought out a way to dissect the concepts from the nervous system, leaving the fluff behind.

The Autonomic Nervous System

Enhancing performance is about balancing stress and recovery, both of which are controlled by the autonomic nervous system (ANS). The ANS has two subsystems: the parasympathetic nervous system and the sympathetic nervous system. That's really where the complication stops, because I'm taking it back to middle school science class.

The sympathetic division excites. It's known for preparing you for either "fight or flight." The parasympathetic division, by contrast, inhibits. It's known for allowing you to "rest and digest."

Remember the story about being in a forest and suddenly encountering a black bear, whereupon your sympathetic nervous system provides an immediate surge of jacked-up energy so that you can get the hell out of there? And when you finally make it to a safe place, your parasympathetic nervous system stops you from feeling like a fiending crack addict?

Knowing when to excite and when to inhibit is crucial to performance. But most times, "knowing" isn't enough because the ANS regulates itself unconsciously. Most people wax and wane between sympathetic and parasympathetic control, which is like idling a car. Sure, you're prepared for action, but you're not going anywhere.

And even though you're not moving, you're still "on," which means you're eventually going to run out of gas. In other words, you don't get shit accomplished and you still pay the price.

Understanding the balance between these two subsystems is important for optimal function, so here are 12 tips to enhance the nervous system's ability to seesaw between stress and recovery to improve performance.

1. Don't dwell over your training.

A good training session is representative of being able to excite the nervous system. After all, training is stressor – it breaks the body down, meaning that at some point you have to respect the body's ability to know when it's okay to destroy itself.

Some guys get all bent when they can't hit a PR or have a bad day in the gym. But you can't linger over what happened last week, last leg day, or even last set. It's likely that the bad day was your body saying, "Not only can't I handle this, but I can't handle what it's going to take to recover from this."

So if you miss your squat PR and do 10 drop sets of leg presses to make up for it, you're going all Plaxico Burress and shooting yourself in the leg. Fact is, if you're having difficulties with what is usually a manageable workload, you probably need to get the hell out of the gym, not create extra fatigue. Save your motivation and excitation for next time.

2. A big event requires a big recovery.

Excitation and inhibition are closely intertwined, making recovery after competition more important than recovery after training. Anytime you perform above your normal capacity (or in an emotionally roused state), you have to recover above your normal capacity.

Keep in mind that this extends beyond competition. If you go to a seminar, or anywhere you're training in front of a crowd you're aiming to impress, you're probably training in an overly excited state.

So when you find yourself training in euphoria, rest appropriately. It might mean a few light or off days, but it can extend further depending on how experienced you are. "For a powerlifter," says Dave Tate, "the most cautious time is four to six weeks after your meet."

3. Don't even think about program hopping.

Envision someone that is high strung. A "worry wart" or someone without an "off switch," as they say. What do they look like? Chances are you pictured them as thin, frail, jittery, and potentially smoking a cigarette or sniffing cocaine.

Stressing over whether you're on the "optimal" program is a death sentence. It leads to second-guessing, which means you'll never stress yourself enough to spur adaptation. Even worse, you'll always be on edge, never letting your parasympathetic nervous system take over. This is the danger of idling.

"Am I doing enough?" "Is what I'm doing working?" These are warning signs. The best athletes don't question their programs. They hit it hard, go home, and get it out of their mind. Have confidence in what you're doing.

4. Relax.

The easier your parasympathetic nervous system kicks in, the better off you are as an athlete. You recover from stressful events faster, which means you can perform at higher levels with more consistency and frequency.

Many world-class athletes have dominant parasympathetic nervous systems, which gets them into trouble because they don't stress themselves beyond necessity. This shows when they apparently "slack off" during practice. But if they're good enough to compete with the rest of the team while only playing at 80% of their capabilities, they aren't going to use the extra 20%.

Turning yourself off is just as important as turning yourself on. Do things that disengage yourself from reality, allowing your parasympathetic nervous system to kick in easier. Ever notice how some athletes play a ton of video games? After practice, they go home, rest, and escape from it all. Although I'd prefer you do something more useful like read a book, there's a lesson there.

5. Nap.

Taking naps and falling asleep quickly are hallmarks of being able to suppress your sympathetic nervous system to expedite recovery. Don't be afraid of it.

"If there's a skill that's overlooked," Dan John says in 40 Years of Insight, "it's the ability to nap when necessary. If my athletes struggle with getting or staying asleep, we're going to have issues down the line. Training oneself to relax is the first step."

6. Pick your aggressive spots.

Sympathetic activation is short lived, and as mentioned, nothing is worse than letting it idle. Turn it on, let it do its thing, and shut it down. Save the heavy metal and head butting for just before your big sets, not during your pre-workout foam roll.

7. Do compound lifts.

The big lifts are far more "exciting" as compared to isolation exercises. They activate more motor units and affect the body on a global level. In the end, it all comes back to the bear-in-the-woods reaction.

Getting stronger and bigger is a protective reaction to avoid death and harm. A 500-pound squat is more life threatening than a 500-pound leg extension. This creates a larger stressor, and larger stressors make the body say, "Holy shit, this is severe. I need to do something so that I'm prepared for this next time."

I don't have any studies to prove this, and I certainly don't recommend it, but I'm sure you'd progress faster on chin-ups if you did them suspended overtop a crocodile infested river.

8. Train hard, recover harder.

A larger sympathetic nervous system excitation warrants a larger inhibition by the parasympathetic nervous system to recover.

High intensity activities that fatigue a large amount of motor units like sprints, plyometrics, and shock training require careful planning so that fatigue can be managed. Just doing more of the good stuff isn't always good. In fact, it rarely is.

9. Reconsider your training split.

Doing a barrage of leg exercises on Monday will affect your capacities on Tuesday. Sure, you can still train, but you won't be as sharp as you could be.

Look at the Westside method. Traditionally, it's all intensity, all the time, either by lifting a personal maximum or maximally accelerating the bar. Bigger, gifted guys can get away with training like this because they need the concentrated stress.

But smaller guys from the less favorable end of the gene pool might be better off following up a high intensity day with a lighter day. Recovery can't happen if you're constantly under maximal duress.

10. Celebrate special occasions.

Disengaging from your "fitness self" on special occasions is hallmark of longevity in this craft. Few things are as relaxing as spending time with family and friends. This is parasympathetic dominance at its best.

Sure, I've gotten up early in the morning to train on holidays. Hell, this year I woke up at three in the morning to train before going on a 10-day vacation. I know a thing or two about hustling, and I don't have a problem with personal inconveniences while working towards a goal. But later, when it's time to sit down and relax, don't be the person that can't enjoy a day of wine, family, and home cooked food.

If you're one of those guys eating clean on Thanksgiving, then I'm not sure I ever want to meet you. As Arnold Schwarzenegger said: "...having a good time is not nearly so damaging as people think."

11. Account for doing something different.

By some margin, the body enjoys the familiarity and comfort that "routine" brings. You can get pretty damn efficient running away from that black bear. Your escape route is planned, you know how fast it runs, and you know its tendencies.

So when the bushes rustle as you're spearing salmon, it's not as worrisome as it once was. But when you look over and see Sasquatch emerge from the greenery, your body behaves like it did when it first encountered the black bear. You don't know if it's fast, if it's hungry, or if it's going to hold you down and sing the entire first act from The Lion King until you beg to be eaten. It's a new stressor. And your body reacts accordingly.

When you rotate your lifts frequently, or do something new, your body gets stressed more than usual. Now, there are some guys that are so advanced that rotating through lifts on a weekly basis is the only way they can spur progress. But for a lot of us, we can stick to the same lifts and see progress just by varying the volume and intensity.

12. Learn how to breathe.

I saved this tip for last because it's the most important of them all, and worth repeating: learn how to breathe.

I first learned about the importance of breathing from Bill Starr, as he wrote about it in The Strongest Shall Survive. Starr detailed a breathing technique he used to calm himself down before lifting in competition (a great example of preventing "idling," by the way).

But along with using breathing techniques to control your heart rate and physiological processes, you need to genuinely learn how to breathe. There are dozens more qualified than I am when it comes to this, but sometime between not wanting to be a fat kid and having six pack ambitions, we adopt a tendency to keep our gut "sucked in."

But by doing this, we don't fully utilize our diaphragm. Instead of sucking your gut in and being a manly man, allow your stomach (specifically, below the lungs) to expand as you inhale.

The next time you find yourself lying on the couch dead-to-rights tired, take notice of how you're breathing. I'll guarantee that your stomach is lax and visibly expanding. That's the way it should be. Remember this for those nights that you're stressed or not sleeping.

What Does It All Mean?

I realize that even though I dismissed the complicated terms, the shit is still complicated. What you need to take away from this, however, is that the body is constantly balancing between stress and recovery.

Being dominant in either sympathetic activation or parasympathetic activation is a very real thing. The great athletes know how to stay "off" and have dominant parasympathetic nervous systems. For the rest of us, however, the most important thing to remember is to avoid idling, as it's death to both performance and recovery.