The Science-Backed Case for a 3-Day Forest Stay in Vermont
I'll be honest — I didn't need a study to tell me that a few days in the woods makes people feel better. I've watched it happen to guests at Tanglebloom for years. Someone pulls up looking like they haven't slept right in a month, and by the time they’re packing up to leave — just-cut bouquet in hand — they look like an entirely different person.
photo Ethan Abitz
But it turns out there is real research behind it, and it's more interesting than "nature is nice to have." One of the most cited studies on this, led by Dr. Qing Li at Nippon Medical School, looked specifically at what a multi-day forest trip does to the body — not a walk around the block, not a weekend park picnic, but an actual immersive stay. And the length of the trip turned out to matter quite a bit.
What the Study Actually Looked At
Starting in 2005, researchers had adult participants take 3-day, 2-night trips to forest areas in Japan, a practice known there as shinrin-yoku, or "forest bathing." Before and during the trips, the researchers drew blood and urine samples to track two things in particular: natural killer (NK) cell activity — a key part of your immune system's ability to fight off infected or abnormal cells — and adrenaline, a stress hormone.
They compared those forest measurements to the same people's readings on a normal working day, and separately, to people who took a comparable trip to a city instead of a forest.
What They Found
The results were striking. According to the study, published in Environmental Health and Preventive Medicine, natural killer cell activity and related immune markers were significantly higher on forest bathing days than on control days — in both men and women. Urinary adrenaline, meanwhile, dropped significantly during the forest trips, a sign the body's stress response was easing off.
Here's the part that really makes the case for booking more than a night or two: the researchers reported that "the increased NK activity lasted for more than 30 days after the trip." A few days in the forest didn't just create a nice memory — it left a measurable trace in participants' immune function for weeks afterward. The researchers noted that a forest trip taken about once a month appeared to be enough to sustain that higher baseline over time.
And the comparison to city travel is what really separates this from "vacations are relaxing, who knew." A comparable trip to the city, taken as a tourist, did not raise NK activity, NK cell counts, or the related immune markers at all. It wasn't travel, or time off, or a change of scenery on its own driving the effect — it was the forest.
Why This Points to Multiple Nights, Not a Day Trip
The study's design is the detail I think gets missed the most: it wasn't a day hike. It was a two-night stay, with measurements taken across the second and third days — meaning the immune response researchers documented built over sustained time in the environment, not a single afternoon walk. If you're weighing whether to book one night or three at a cabin surrounded by woods and fields, the research suggests the extra nights aren't just a nicer trip. They may be doing something the first day alone doesn't.
That tracks with what I see at Tanglebloom, too. The first night, most guests are still decompressing — checking their phones, half in work mode. It's usually day two or three when something shifts. Their shoulders drop. People actually open the book they brought. Their walking pace slows. That's not a coincidence; it looks a lot like what the data shows.
What This Looks Like at Tanglebloom
You don't need a Japanese cedar forest to get some version of this. Tanglebloom sits on a working flower farm at the edge of the woods in Brookline, Vermont, minutes from Brattleboro — surrounded by trees, trails, and quiet in exactly the way this research points to. A 2-3 night stay gives you the same basic ingredient the study relied on: sustained, unhurried time outside, away from the noise of your regular life.
If you've been telling yourself a night away is basically the same as a longer getaway, the research says otherwise. The forest seems to need a little more time with you before it does its best work.
