"Stress is related to 99% of all illness," reads the bag of Lululemon, the high-end stretchy pants emporium on Walnut Street.  While the researcher in me can't help but gawk at this claim and demand that the store cite its sources, the words are not all wrong.

Stress can make you sick, this much we know. Ever since Hungarian endocrinologist Hans Selye coined the term "stress" some 75 years ago, scientific research on the role of stress in the formation of disease has grown immensely.  What has received less attention, however, is the question of what we can do about it.  One possible answer is simpler than you might think.

Expressive writing (explained in this 5-minute video) — or "written emotional disclosure," as it's known in academic circles — is a basic writing technique that has been found to improve physical and mental health among those who practice it.

Developed by psychologist James W. Pennebaker, the first experiment on the health benefits of expressive writing was published in 1986. The study found that college students who were told to write about a traumatic event visited the campus health center less often than those who were told to write about trivial topics.

Since then, well over 100 randomized controlled studies have demonstrated the benefits of expressive writing across a wide range of health outcomes, including asthma, immune system function, smoking cessation, and many others.

How and why does expressive writing work? Theories abound. Proponents of inhibition theory believe that it takes energy to suppress feelings, and that this wears on the body over time.  The disclosure of these feelings is thought to provide release — a phenomenon that Freud referred to as catharsis.

Interested in giving expressive writing a try? Here's how you do it:

  • Find a safe and quite place to write. A time at the end of the work day or before going to bed is recommended.

  • Pick a topic. It could be something you've been worrying or thinking a lot about, something from the past that you're angry about, or a traumatic event that you may not have shared with many other people.

  • Write.  The standard protocol is writing for at least 15 minutes (you can go on as long as you want, though) for three or four days in a row.  You can write about the same topic each day or switch it up. You can either write by hand or type on a computer. Don't worry about spelling and grammar — just let it flow.  You might feel a bit upset or emotional right after you finish, but these feelings should subside in a few hours.

  • What should you do with what you write? It's entirely up to you.  You can save it, revise it, publish it, delete it, rip it up, burn it, read it aloud, frame it, make origami out of it, the choice is yours.

Stress, like health and illness, is a part of life.  Chronic stressors, such as a hectic daily commute or worrying about finances; major life upheavals, like the death of a loved one or loss of a job; and traumatic events, such as witnessing or being the victim of violence, all exact a toll on our bodies and our minds.

As much as we like to think that we can let these stressors go at the end of the day, our minds and bodies can't help but hold on to them.  Expressive writing provides a tool to help send stressors on their way, making room for things in life that really matter. Like $150 spandex.

Read more about The Public's Health.