Twitter's chief executive Jack Dorsey has revealed he takes daily ice baths and eats only one meal a day in an in-depth interview about his extreme fitness routine.
Appearing on a fitness podcast, the billionaire said the "biggest impact" on his mental health has been meditation but said he also does weekend-long fasts to give him the focus and energy to run two companies.
The 42-year-old has been meditating for 20 years and spends an hour each morning and evening on the spiritual practice, he told the Ben Greenfield fitness podcast.
He has came under fire last year for attending a 10-day meditation retreat in Burma with Twitter users accusing him of ignoring the country's human rights abuses. He later said he needed to "learn more".
Mr Dorsey, who co-founded the platform Twitter and mobile payments company Square, said his daily routine includes fasting for 22 hours a day and walking the five mile commute to his office.
I did my meditation at Dhamma Mahimã in Pyin Oo Lwin. This is my room. Basic. During the 10 days: no devices, reading, writing, physical excercise, music, intoxicants, meat, talking, or even eye contact with others. It’s free: everything is given to meditators by charity. pic.twitter.com/OhJqXKInD3— jack (@jack) December 9, 2018
The daily walk allows him to spend time thinking or listening to podcasts. “I might look a little bit more like I’m jogging than I’m walking... I try to get as much sunlight as possible and then I begin the day 9," he said.
The tech chief said skipping breakfast and lunch frees up his day and makes him more productive. His dinner usually consists of meat or fish accompanied with a salad or green vegetables, followed by some fruit or dark chocolate.
“During the day, I feel so much more focused... the time back from breakfast and lunch allowed me to focus more on what my day is,” he said, adding that it allows him to sleep better.
Mr Dorsey also said he uses a sauna and ice bath for "mental clarity" every evening. He sits in a barrel sauna set at 220F degrees (104C) for 15 minutes followed by three minutes in an ice bath set at 37F degrees (2C).
Rather than easing up on himself on weekends, Mr Dorsey said he has trialled 48-hour fasts from Friday to Sunday evening during which he only drinks water.
“The first time I did it, like day three, I felt like I was hallucinating. It was a weird state to be in. But as I did it the next two times, it just became so apparent to me how much of our days are centered around meals and how - the experience I had was when I was fasting for much longer, how time really slowed down,” he said.
Earlier this week it also emerged that Mr Dorsey was received a total salary of just $1.40 from Twitter last year, a nod to its former 140-character per tweet limit.
"As a testament to his commitment to and belief in Twitter’s long-term value creation potential, our CEO, Jack Dorsey, declined all compensation and benefits for 2015, 2016 and 2017, and in 2018 he declined all compensation and benefits other than a salary of $1.40," a section of the company's filing stated.
However, Mr Dorsey owns 2.3 per cent of the company's stock. He also made an estimated $80 million (£61 million) after taxes from selling 1.7 million shares in his second company Square, according to Forbes.