Hormesis: The Helpful Stress

In the Paleo world, we talk a lot about reducing and managing chronic stress: that’s the daily traffic grind, the constant low-level money problems, the cubicle mate you can’t stand. Our hormonal response to stress was designed for short-term, acute stressors; when we have that “you’re being chased by a lion, run away!” response turned on all the time, our bodies simply start breaking down.

The list of evils caused by chronic stress is long and familiar: insulin resistance, gut flora dysfunction, leaky gut, impaired immune function, sleep disturbances…you’ve heard them all, and they’re all real.

That’s all true, but it’s only half the picture. We weren’t designed for chronic stress, but we also weren’t designed to hide away at home from anything that could potentially be challenging. Some kinds of stress – the stressors that we are designed for – are actually good for us. Three examples: high-intensity workouts (followed by an appropriate amount of rest), dietary antioxidants, and intermittent fasting. We don’t usually think of these as “stressors,” but in the technical sense of the word, they all are: all of these things challenge your mental and/or physical capacity. That’s what stress is.

Hormesis: Stress that Makes you Stronger

The difference between a “good” stressor and a “bad” stressor is that you bounce back from the “good” one stronger than you were before. This is called hormesis: growth through responding to a low or intermittent dose of a stressor that could be dangerous or deadly at a higher level. If you jump off an ice floe in the Arctic in winter, you’ll (probably) die, but a little time in a cold bath, can improve your immune function.

Not all stress is hormetic stress, but some of the most common stressors can be, if they’re done right.

The most obvious example of hormesis in action is strength training. Say you come in as a complete beginner and you can only squat the bar (45 pounds). Your coach has you squat with the bar for 5 sets of 5; you go home and eat some high-quality protein and healthy carbs, and get a good night of sleep.

The exercise actually damages your muscles, and increases levels of oxidative stress and inflammation in your body. You’re actually getting a relatively low but manageable dose of muscle injury (which you might feel in the form of soreness the next day). But at the same time, the training stimulates anabolic hormones like growth hormone and testosterone. When your body heals those tiny injuries, it builds up some new muscle fibers to go along with the newly-repaired tissue. Also, the increase in oxidative stress provokes a “supercompensation” from your own antioxidant defenses, so you end up with lower levels of inflammation in the long run.

Sleeping allows your body to do all this while creating the proper environment for rest and muscle repair. While you snooze, your body uses all that protein you just ate to repair the muscles, and the carbs to top up your fuel stores for the next workout.

In your next workout, you might be able to squat the bar for 5 sets of 6 – or alternately, you might go for the bar + 10 pounds (55 pounds total) for the same 5 sets of 5. Either way, your body has become stronger and your work capacity has improved. Then you go home, eat protein and carbs, get enough sleep, and repeat the cycle. In the long term, your levels of oxidative stress will decrease while you get stronger and more resilient to oxidative stress in general.

Dose and Recovery

Hormetic stress depends on a manageable dose + recovery. To bounce back and get stronger, you have to keep the “dose” of stress reasonable and actually give your body time to bounce back. Exercise can be a hormetic stress if you recover from it appropriately, or it can be a chronic stress if you keep overtraining and under-recovering (that goes double if you’re also under-eating). Constantly training to failure in every workout actually reduces the muscular adaptations of exercise.

Under-recovering can transform any stress into a dangerous chronic stress, regardless of how beneficial it could have been under the right circumstances. Not all stress can be hormetic – there are no known benefits to sitting in traffic grinding your teeth – but all stress can be damaging if you apply it incorrectly.

How to Get Stronger with Hormetic Stress

That was the theory behind hormetic stressors: chronic stress wears us down, and overwhelming stress can kill us very quickly, but intermittent and relatively low doses of stress followed by enough recovery time can actually make us stronger. Here’s how to put that into practice.

Challenge Yourself…

Not just in the gym, although that’s one way to do it.

• Occasionally push your workouts. Try something ambitious – a half-marathon if you run, or a planned program of higher intensity lifting followed by a rest week or two. You can gain from this mentally as much as physically. Make sure to match the intensity of your “stressor” to your recovery capacity!
• Go on adventures. Do things that scare you. If you’re 100% comfortable the entire time, it’s not an adventure.
• Try fasting. Intermittent fasting is a form of hormetic stress. (Unless you’re doing it on top of a grueling exercise routine, a steep calorie deficit, a chronic sleep debt from getting up at 6am to go to the gym, and a full-time job. Then it’s just another straw on the back of your chronic-stress camel).
• Eat antioxidant-rich foods. Antioxidants are actually hormetic stressors.
• Try cold therapy. Cold exposure is a hormetic stressor that can increase immunity.

…And Then Recover.

The old saying “what doesn’t kill you makes you stronger” is really only correct with an addendum: “what doesn’t kill you makes you stronger…if you have a chance to recover from it.” Otherwise, it just wears you down.

The harder you push, the more seriously you need to take your recovery. How you recover will depend on what your body needs, but here are some ideas:

• An hour or two of extra sleep can sometimes do more good than all the foam rolling and supplements in the world. Your body is the world champion at healing itself; you just have to lie back, close your eyes, and let it do its job.
• Extra nutrient-dense food, especially if your form of challenge is calorie-intensive.
• Mobility work as appropriate. If you’re getting into any athletic endeavor seriously enough to get sore and stiff, you should also be looking into the best mobility work for that sport.
• Basically adequate calorie and nutrient intake. It’s one thing to fast intermittently; it’s a completely different thing to be chronically under-nourished. Remember that calorie restriction is a stressor.
• Manage chronic stressors. This will help you recover faster from the stressors you choose.

Summing it Up

“Managing stress” doesn’t mean avoiding all potential stressors and curling up into a fragile little ball on the couch with a safety helmet on. Humans are tougher than that. “Managing stress” means reducing the chronic stressors that just suck away your energy without giving you anything back, but embracing the hormetic stressors that make you stronger and more resilient by challenging you.

This is the kind of stress that we are adapted to: a short period of intense demand, followed by a longer period of rest. That kind of stress (as long as it’s followed up by appropriate recovery) actually makes us stronger in the long run.