The clientele at Maha Yoga is what you might expect at 4pm on a Saturday at a studio in Los Angeles: high-powered female lawyers and their preteen daughters, muscle-head male models, and a smattering of NPR (National Public Radio) listeners. Then Woody Harrelson walks in the side door, red-eyed, stubbled and bleary. He’s come straight from Los Angeles airport. “I just got back from Kentucky,” he says in his familiar laid-back drawl.

“I was working with a scientist on a new invention that will revolutionise how we clean up sewage. It’s cool. Usually our government treats our toxic sewage waste with even more toxic chemicals, then declares it safe for drinking. The method we’re developing does it without chemicals, and it’s 85 to 90% clean when it comes out. I think we’re gonna start with hog waste.”

He claps his hands together. “All right!” he says. “Let’s do some yoga!” He unzips his hemp yoga bag (which goes with his hemp yoga pants), removes his hemp yoga mat, unrolls it 10 yards behind me, and starts to stretch. The instructor glides into the room. “I know that dude,” Woody says. The dude knows Woody, too. “Hey, what’s happening, Woody?” “Not much, man,” Woody says. “Good to see you back!”

An hour and a half later, after a vigorous class, we’re lying perfectly still on our mats in the quiet, low-lit room. As the yogi starts to talk us back to full consciousness, there’s a loud, hacking snore. Even as we’re told to open our eyes, the snore continues. I look behind me. Woody is lying on his mat, snoring away. If this were a cartoon, he’d be keeping a feather aloft. We sit up cross-legged. He’s still snoring. The entire class chants “ohm” together. Woody sleeps on through, even when the lights come on. Finally, he snorts awake, looks around, and hops up bright-eyed and refreshed, as if he’d just slept 10 hours. “I always fall asleep during shavasana,” he says. “It’s the best rest I get.”

“Woody” the bartender from Cheers is a distant memory now, and the leading-man Woody of Indecent Proposal, Natural Born Killers, and The People vs Larry Flynt is in deep rerun mode on cable. Even Harrelson’s best-known political actions – getting arrested for scaling the Golden Gate Bridge to protest the logging of California redwoods, and for planting hemp seeds in Kentucky – are more than a decade ago. Today’s Woody, 46, is a mature model, less in-your-face. After years of soul-searching, including a virtual five-year hiatus from film acting, he’s fully at ease with himself, but still unique, even deeply strange. As an activist he’s Abbie Hoffman crossed with Al Gore, using his winking charm to put people at ease, then subtly bending the room to his will. As an actor he’s found a new niche: taking on eccentric, challenging, often supporting roles in movies he wants to do. It’s kept him busy. He’s in half a dozen films this year alone, from the new Semi-Pro (a comedy set in the 1970s starring Will Ferrell) to the quieter Battle in Seattle (an indie docudrama about the 1999 World Trade Organization – WTO – protests) to Management (a Jennifer Aniston romcom).

Lately, Harrelson has been working with some of the best directors (Robert Altman, Oliver Stone, the Coen brothers) while trying to develop a multi-billion-dollar process that would mass-produce paper without wood pulp. Under the stoner facade is a guy who gets things done.

Kent Alterman, the director of Semi-Pro who cast Woody as the veteran player of a basketball team, tells an interesting story. “Woody, between sets, was always playing basketball. He had an uncanny ability to have fun and have an awareness that he was performing. We had this crowd of extras, who he kept engaged and entertained. He’d start trying crazy shots backwards over his head at half-court. He had everyone watching him, and at a certain point he’d hit the shot, and people would go crazy.”

It’s the same dramatic flair he employed in 2001 when he rode a bike from Seattle to LA accompanied by a biofuelled bus, to advocate leaving a lighter carbon footprint. The trip was made into a documentary, Go Further.

The two Woodys, the crowd-pleaser and the rabble-rouser, may seem at odds, but not to Woody. “A pretty amazing thing happens in this industry when you have success,” he says. “Everyone tells you you’re great, and you become like world royalty. Wherever you go, doors open. In one sense it’s wonderful, but in another it narrows your focus, so you end up becoming a little too self-focused.”

A number of factors led him to have a break from Hollywood in the early 2000s. A political backlash against the Larry Flynt film – a role that brought him an Oscar nomination – slowed down the leading-man offers, he says. And he made a conscious decision to back away from the “hedonism/narcissism” and instead “hang with the fam”.

“It was gonna be a couple of years, then it turned into five,” he says. “Best decision I ever made.” His journey led him to Maui, where he lives with his wife, Laura Louie (an environmental activist and his former assistant), and their three daughters (aged 1 to 15). They live in a remote coastal town called Kipahulu, a place where there are no shops other than an adjacent organic farm called Laulima, which has baked goods for sale. Residents make poi (woven flax) at a community centre and allow no genetically modified organisms to cross the town’s boundaries. Woody has been there for about eight years now, after being introduced to the Maui way of life by his good friend Willie Nelson.

“I’m sure glad I found it,” he says. “It’s an amazing community of people. It’s off the grid, there’s no power lines. Most of the people there, including us, run their vehicles, tractors and stuff off biodiesel. We all get together for Thanksgiving and look after each other’s kids. It’s a real community, like one I’ve never been a part of in my life.”

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