The Science of Expressive Writing: How Journaling Became a Tool for Health, Performance, and Growth
The field of expressive writing, the practice of putting thoughts and emotions into words, began in the 1980s and has evolved into a powerful tool used in medicine, psychology, and even sports performance. Here's a guided walkthrough some major moments, from the early experiments to today's AI-powered journaling.
1980s – The First Breakthroughs
It all started with psychologist James W. Pennebaker. In 1986, his landmark study asked participants to write for 15–20 minutes a day for four days about the most difficult experience of their lives. The results were striking: those who wrote about emotional events had fewer doctor visits afterward compared to those who wrote about neutral topics.
The idea—now called the emotional inhibition hypothesis—was simple but profound: bottling up emotions can create stress in the body, while writing helps process and release them. His work set the foundation of journaling and expressive writing as a real tool to make us healthier.
1990s – Linking Writing to Physical Health
Then the research expanded.
- Joshua Smyth showed in a 1999 medical trial that expressive writing improved lung function in people with asthma and reduced disease activity in arthritis patients.
- Susan Lutgendorf found that writing could boost immune markers in people living with HIV or recovering from cancer.
- Laura King introduced the Best Possible Self exercise, showing that writing about your ideal future could increase optimism and life satisfaction for months.
For athletes, this was an early signal, that writing can influence the mind-body connection and have real impact.
2000s – Understanding How It Works
Researchers started digging into the mechanics.
Pennebaker's team developed Linguistic Inquiry and Word Count (LIWC), a tool that analyzes the words people use in their writing. They found that improvement often came alongside a shift in language—more causal and insight words like "because" and "realize," showing the mind making sense of events.
A 2005 review by Karen Baikie and Kay Wilhelm summed it up: writing works best when it's emotional, sustained, and turns experiences into a coherent story.
2010s – Sport, Gratitude, and Resilience
This is when expressive writing entered the athletic space.
In 2012, Hudson & Day studied athletes writing about sport-related stress. Both traditional expressive writing and a "reframing" version helped athletes manage emotions and problem-solve, with reframing especially good at turning stress into a challenge mindset.
At the same time, positive psychology researchers—led by Martin Seligman—popularized gratitude journaling and "Three Good Things" exercises, showing they could lift mood and reduce depression over time.
2020s – Tech, Personalization, and AI
Today, the practice is meeting technology. Language analysis tools, voice-to-text and app-based journaling are making journaling more approachable, easier, and faster. AI journaling apps can now help tailor prompts to your goals.
Why This Matters for Athletes
The evidence is clear: journaling is a researched skill for processing stress, clarifying goals, and supporting both mental and physical performance.
Whether you're writing to get through a tough training camp, to prepare for a competition, or to reflect on your best moments, you're part of a long tradition of athletes and scientists exploring the power of words.
Sherpa makes it easy for athletes.
Sherpa makes it easy to start by providing simple prompts, voice-to-text, and AI-powered insights over time. Start by setting a goal for practice or training and reflecting after. It's free in the app store.