Zachary Rapp wakes up most mornings at the crack of dawn, goes for a run, sips black coffee while ripping through emails, and then steps into a freezing cold shower.
It's a routine designed to reduce the stress of juggling three different health and biotech start-ups for 18 hours a day.
Rapp is part of the growing "positive stress" movement, consisting of tech workers who claim that such radical tactics will help them live better and longer or — in Silicon Valley — work better for longer.
Inspired by influencers in entertainment, entrepreneurship and science, the positive stress practitioners seek out some combination of extreme temperatures, restrictive diets, punishing exercise routines and general discomfort. There's also whole body cryotherapy — electric walk-in cold chambers — popping up at spas across the country.
"Right now I'm trying to push through an inhuman amount of work," Rapp told CNBC.
Rapp is co-founder of digital health start-up PhenoMx; the CEO of SigmaGenetics, which makes a non-invasive device that's trying to deliver DNA into cells using magnetic fields; and the head of business development at medical device maker Altoida.
"It keeps me balanced," Rapp said, referring to ice baths, hot yoga, intermittent fasting and the Whole30 diet he'll try next month, which requires cutting out grains, legumes, dairy, sugar and alcohol. "Like the stress is leaving my body, so I don't feel like I'm hitting a brick wall."