If your doctor were to write out a list of the top 10 things to minimize in order to live a long, healthy life, stress would most definitely be at the top. Study after study has shown that excessive stress can literally kill you. (Not to be dramatic or anything.)

While those studies are legit, the truth is a bit more nuanced than just issuing a blanket statement that stress is always bad. Many scientific studies show that small bursts of stress can actually help you live longer, a process called hormesis.

Intrigued? Keep reading to learn more about what hormesis is and how to apply just the right amount of physical stress to your life to reap the benefits.

What is hormesis?

The term hormesis was coined in the 1940s, and is often used in the context of toxicology (aka the study of how harmful chemicals and substances can impact people, animals, and the environment). In this context, it is defined as “a phenomenon in which a harmful substance gives stimulating and beneficial effects to living organisms when the quantity of the harmful substance is small.” Basically, if an otherwise-toxic substance can be beneficial to the body in very small amounts, it is considered to be hormetic.

This theory has since been applied to the fields of biology and medicine, which is what we’ll be focusing on here. In this context, “hormesis is a process where the body responds positivity to small [physical] stressors,” explains top functional medicine doctor Frank Lipman, MD, whose new book The New Rules of Aging Well ($25) is out now. “Chronic stress has a negative impact on the body, but small stressors are actually positive, especially in terms of longevity.”

Raymond Berry III, PhD, who has studied hormesis in animals, explains it this way: “There’s a curve to hormesis where the top of the curve represents the benefits, but if you go past that point, it then starts to become detrimental,” he says. The key is hitting the sweet spot.

How exactly does it work? Dr. Lipman says that small bursts of intense stress stimulate the body’s mitochondria, which convert food and oxygen into energy (adenosine triphosphate, or ADP, if you want to get technical) for cells to use. “ATP molecules are especially abundant in the heart, brain, and muscles,” Dr. Lipman says. “This is why it’s so beneficial to stimulate the body’s mitochondria; it plays a key role in these major organs and when they start functioning not as well, that’s when you really notice the effects of aging.”

Stimulating the body’s mitochondria is a “longevity pathway,” Dr. Lipman says, because small bursts of intense stress cause the mitochondria to adapt, slowing their natural decline (which is associated with premature aging). “It’s really this idea of ‘what doesn’t kill you makes you stronger,'” Dr. Lipman says. That is the beauty of hormesis.

What does hormesis look like IRL—and how much is beneficial?

Both Dr. Berry and Dr. Lipman say there are many ways to induce hormesis, but perhaps the three easiest (and safest) to achieve are (super) cold showers, high-intensity interval training, and intermittent fasting. They explain that all three methods stimulate the body’s mitochondria, which in turn stops cells from accumulating damage as quickly.

“In terms of cold showers, research shows that it ups the production and health of your mitochondria,” Dr. Lipman says. One study using mice showed that mice routinely exposed to the cold for eight weeks experienced better muscle function and performed better at exercise than mice who weren’t exposed to the cold.

There are other benefits to cold showers as well—and you just need to stay in for a few minutes in order to enjoy them. “Cold showers wake up your skin receptors, which causes increased activity to the brain,” dermatologist Michele Green, MD, previously told Well+Good. The habit can also increase serotonin levels, leading to a mood boost. “A lot of people will take a cold shower to feel more energized or focused,” Dr. Berry says, adding that this is a common practice in Traditional Chinese Medicine too; cold showers are said to get your chi (energy) flowing.

Watch a video of what it’s like to take an ice bath on the roof of a freezing cold New York City day:

Meanwhile, “HIIT workouts stimulate the same longevity gene pathways as a cold shower,” Dr. Lipman says. HIIT workouts have been found to improve mitochondrial function; a small study showed that older adults who did HIIT workouts on a regular basis “increased mitochondrial content which may help to maintain muscle oxidative capacity and slow down the process of sarcopenia [loss of skeletal muscle mass and strength] associated with aging.”

Dr. Lipman says that HIIT workouts are specifically crafted so the amounts of physical energy being exerted are just enough to get the benefit. (Although, as with any workout, there is always the risk of injury.) “During [these] microbusts, you should be working so hard and breathing so hard that you can’t chat,” Dr. Lipman writes in his book. One example he gives of how to put this into practice: ramp up for one minute, go hard for one minute, go back to a comfortable pace for three minutes, and then repeat. “If your body is reaching the point where you’re in pain, then you’re taking it too far,” he adds.

With intermittent fasting, Dr. Lipman says many studies have linked intermittent fasting to longevity, largely because it reduces caloric intake (albeit in a subtle, smaller way). “One study [on monkeys] found that subjects who reduced calories by 30 percent lived longer and even avoided some age-related diseases than those who didn’t,” Dr. Lipman says. “This is because short bursts of fasting puts a little stress on the body; however excessive food restriction would be harmful.”

But fasting, however, isn’t as intuitive. Dr. Lipman emphasizes that it’s never beneficial to stop yourself from getting the nutrients your body needs and says this mode of hormesis isn’t right for everyone. “For example, if you are pregnant or just had a baby, you need to eat more frequently,” he says. But for the average person with no underlying health conditions or a history of disordered eating, Dr. Lipman says intermittent fasting is another way to try this form of hormesis and there are different ways to go about that. (He tends to recommend the 16:8 method, where you restrict eating within an eight-hour window of the day.)

While all these forms of hormesis are very different from each other, both Dr. Berry and Dr. Lipman says they activate the same response in the body, which is stimulating the body’s mitochondria. “As you get older, cellular function and the ability to repair diminish,” Dr. Lipman writes in his book. “The body can better repair damage when you give it these small acute stresses. Your body is always working to repair itself, and hormesis helps.”

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