Adriene Mishler's eyes are shining with tears. We meet near the end of a six-week sellout European roadshow that has taken in Berlin, Stockholm and Amsterdam. In London she has taught classes of over 2,400 people packed into Alexandra Palace, complete with stage lighting, loud music and merchandise stalls.
Next up, Paris. It's been "gruelling". These could rightly be tears of exhaustion. But no, it's joy that she's radiating. Because Mishler is grateful. Very grateful.
The Texas native who wanted to be an actress has instead found global success as a yoga teacher. Hers is the name on every beginner yogi's lips. Try casually asking a friend where you might find a good online yoga class and prepare to be told with die-hard seriousness: "Adriene changed my life."
With over four million subscribers to her 'Yoga With Adriene' YouTube channel and over 18 million views for her 20-minute 'Yoga for Complete Beginners' video, alone, her free classes - filmed in her dining room in downtown Austin, with her black and white blue heeler, Benji - have become a gateway for those unable, whether financially or physically, to get to a yoga class.
Yes, it might be her excellent Google ranking that first brings you to her page (type 'yoga' into the search engine, and the first video that comes up is hers) but it's the mix of friendly encouragement and self-deprecating humour that makes you stay. In an online yoga world full of perfect handstands and pretzel poses, she laughs at her creaky legs, forgets her words and reminds you that you don't have to be an acrobat to practise yoga, you just need to "find what feels good".
Yet, even Mishler can't quite comprehend what a phenomenon she is.
"I get emotional just thinking about everyone because for years, nobody knew or cared, even my parents were like, 'Cool'... like they didn't get it. But now it's a joyful thing. I think they are proud and I'm proud of everyone involved - it's not just me, it's every single person who has ever subscribed and watched and everyone who believes in it," she says in a seamless, tearful flow.
Days after our interview, I watch Mishler take to the stage of London's Oval Space to the sound of Nina Simone's 'Feeling Good' and guide over 200 yogis, female and male (yes, men love her too), inhaling and exhaling in unison. The love in the room for her would feel a little cult-like if she weren't so darned lovely. And yes, this sort of adulation does make her squirm. She prefers the term 'roadshow' to 'tour', she says: "I'm no rock star. I'm not your guru."
The irony is that having trained as an actress in New York, fame could well have come on the red carpet. But yoga was always part of her life. Growing up in Austin with actor parents, they would focus on body, breath and voice - "I think we even did sun salutations for warm-ups" - and aged 17, she would drive her "clunker junker Volvo" to the only yoga studio in Austin (there are at least 30 more now). A year later, she qualified as a teacher. Besides being something she loved, it was a way to earn money on the side while she pursued a career in film and theatre.
It was on the set of an indie horror film that she met the director Chris Sharpe, who would eventually become her business partner. After the film fell apart in 2010, he suggested they collaborate on a YouTube channel. Finally, in 2012, 'Yoga With Adriene' was born.
Success wasn't immediate. For the first three years she still swept and mopped floors at her local yoga studio in exchange for free classes. She might now have a sponsorship deal with Adidas, but for a long time she owned just three pairs of yoga pants: "And one had a hole in the butt that I had to try to hide. It's the truth. I didn't know when the rent was coming for many years."
In 2013, a big break in a Hollywood movie, Joe, starring Nicolas Cage, brought her to a crossroads: "It doesn't get any bigger than that, you know? I pressed my bare chest up against Nicolas Cage's back," Mishler laughs.
But while in New York for the premiere, she hosted her first yoga meet-up for fans already following the channel. There was no team, just Mishler and her cousin Alicia, who helped her with the liability forms for the 40 attendees.
Times have changed. Mishler is loathe to put a figure on her YouTube revenue, which is "always fluctuating", but thanks to some savvy SEO - videos with titles like 'Yoga for Weight Loss' and 'Six-pack Abs' have done very nicely - membership to her video subscription website, Find What Feels Good, is now close to 15,000, each paying $10 (around €9) a month.
Yes, she owns more yoga pants now, but the money - besides paying her bills, dog-sitter and small team - means she can keep her yoga free, "for all the people who can't afford it".
If anything, success negatively affected her life at first. Four years ago, as her most popular video series, 30 Days Of Yoga sky-rocketed, Mishler's personal life fell apart. Not only did she need potentially career-ending vocal surgery, but life on the road - eating alone, feeling alone and missing her boyfriend and dog - left her feeling fractured. And creating constant video content can be draining: "When I don't feel up for the task, when I have a big pimple on my face, when I'm in the middle of a break-up or when my dog died," she says.
Long-time followers will recall her old house, with its lime green walls and creaky old floor, which was the one she shared with her ex - "who, by the way, is amazing, my friend and a huge supporter" - and her first dog, Blue, "my baby for all of my 20s".
For the last two years, she has lived alone, taking better care of herself and considering where to go next. She still loves theatre, and has taken the odd acting role, but is "no longer interested in becoming a famous actress. I'm famous enough".
And despite the workload, there's always time to party. Her team joke about being 'FOFO', full on or full off. "I will go weeks, months without any alcohol, just going to bed early, pretty pious, truly. But then I'll finish one project and then all of a sudden, it's 'garden party and prosecco' all day."