Happy Monday {{first name | my friend}},

Last week I heard the first elk bugle near our house. That sound is a strong indicator of fall around here. Bulls (males) are advertising themselves to the cows (female elk) and warning off other bulls, and they'll keep at it into November, loudest after sunset and before sunrise.

It's Labor Day, so if you’ve got the day off, I hope a good piece of it happens outside. Here's what caught my attention this week.

🩺 HEALTH HACK: The bacteria living on the back of your tongue convert dietary nitrate into nitrite, which your body then turns into nitric oxide, the molecule that relaxes your blood vessels. Antiseptic mouthwash wipes out those ‘good’ bacteria at the same time as the ‘bad’ ones. In a three-year study, adults who rinsed twice a day or more developed high blood pressure at more than double the rate of people who never used it.

✨ MAGICAL PLACE: In northeastern Brazil sits a 600-square-mile field of white sand dunes that fills with thousands of turquoise rain pools every year. Some of the lagoons at Lençóis Maranhenses stretch 300 feet and run warm enough to swim in (you need to see the pictures). Something called wolf fish live here, burrowing into the mud and going dormant when the water evaporates, then surfacing when the rains return.

🤔 DID YOU KNOW?: Hummingbirds drop into a nightly state called torpor, letting their body temperature fall more than 20 degrees while their metabolism slows by as much as 95%. In midsummer they only do this when fat stores run low, but in late summer they'll enter torpor while carrying up to 40% body fat, banking energy for the flight south.

🏡 HEALTHY HOME: Before the furnace kicks on for the season, find out what your indoor humidity is. Forced air pulls most homes below 30% relative humidity, which dries out the mucous membranes that trap viruses before they get anywhere. Stanford chemists found that raising humidity from 15% to 50% multiplied hydrogen peroxide in airborne droplets by 3.5x, which is a disinfectant the air makes on its own. A humidifier in the bedroom will hold you in the 40 to 60% range.

🍽️ NUTRITION 101: Mushrooms produce vitamin D the same way your skin does, and can keep producing even when you bring them home. Researchers set sliced white button mushrooms outside for 15 minutes of midday sun and measured huge gains of vitamin D per serving, with oyster and shiitake even higher. Set the gills facing the sky, since that's where the conversion happens. Slice, set them on the porch while you make lunch, and then cook as usual.

🌱 REGENERATIVE FUTURE: Two years after the last of four dams came down on the Klamath River, more than 20k chinook have pushed upstream, and recolonized roughly 90% of their historic range. They reached the upper basin within months, the first time in over a century. Recovery is still fragile with low snowpack, but the fish found the river faster than anyone predicted.

Mornings here have started dipping into the 40s, and I've been experimenting with what drinks give me the best start to the day. Pique's Pu'er Tea Duo is a fermented tea, which means the leaves keep fermenting after they're picked and processed, closer to what happens in a crock of sauerkraut than in a standard tea bag. People in Yunnan have been drinking it for roughly 1,200 years, mostly for digestion and steady energy.

Black in the morning, green in the afternoon. Both come as crystals in single-serve sachets, pulled from 250-year-old tea trees in the Himalayan foothills and cold-extracted rather than heat-processed, so the polyphenols and live cultures make it into the cup. The black runs 58 to 87 mg of caffeine, the green 41 to 61, so they don't hit you like an espresso.

After a summer of road food and late dinners, it's such an easy addition back into my routine. You can get 20% off with a subscription, and it's backed by a 90-day promise, so you've got three months to decide whether it's working for you.

Which is your favorite season, if you had to choose one?

🟦⬜️⬜️⬜️⬜️⬜️⬜️⬜️⬜️⬜️ ❄️ Winter (4.2%)
🟩🟩🟩🟩🟩🟩🟩⬜️⬜️⬜️ 🌷 Spring (31.2%)
🟨🟨🟨🟨⬜️⬜️⬜️⬜️⬜️⬜️ ☀️ Summer (18.8%)
🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧 🍁 Fall (45.8%)

To a healing future,

— Rob