[Editor’s note: The following contains some spoilers for Season 2 of Physical.]From show creator Annie Weisman, the Apple TV+ original series Physical has ramped things up for Season 2, with Sheila Rubin (Rose Byrne) focused on building her business into a fitness empire and turning herself into a brand, with the help of her husband Danny (Rory Scovel) and friend Greta (Dierdre Friel). Although Sheila is finding that she has a bit of competition when it comes to world fitness domination, and she has to decide just how far she’s willing to go for success.

During this interview with Collider, co-stars Byrne and Friel talked about why Sheila is such a scary character to play, bringing a bleeding heart like Greta to life, the strength and the toxicity that are both present in Sheila’s inner voice, Greta’s loyalty to Sheila, the fight between their characters in episode seven, getting to dance, and how they hope to get to continue telling chapters of this story in future seasons.

Collider: Actors often talk about wanting to find and play characters that scare them, in some way. Rose, was Sheila, one of those characters for you? Does she scare you, or is she just a lot of fun?

ROSE BYRNE: No, she’s very scary. I’m always scared of any character. I’m terrified of doing it and showing up. It’s daunting, absolutely. The world of this is so very much what I wanted to step into and, in many ways, Sheila could be the last point of entry. The whole world is just so specific and wonderful, and it’s such a true story to Annie Weisman, our creator, and showrunner. She’s been incredibly candid with me about her own experiences with bulimia. She’s my touchstone for everything, so I hang onto her, but we have a great cast and crew. It’s a lovely group.

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Image via Apple TV+

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Dierdre, what about for you? Are there aspects of Greta that scare you, or is she someone who you have fun exploring all of her eccentricities?

DIERDRE FRIEL: Yes, both of those things. Greta is so open, and she’s such a reactive bleeding heart type of person. That’s wonderful, as an actor, but also, every time I read a scene where I have to completely freak out, even in makeup that morning, I’m like, “I’m not gonna do it. I’ll never get there.” But then, somehow, when you put the work in, you have great acting partners, the writing is fantastic, and the direction is right, you get there. And so, I would say that’s the part that I enjoy the most, but also feel nervous about.

Rose, it feels like no one hates Sheila as much as Sheila hates Sheila. Do you feel like that little voice in her head really is the biggest villain of her story?

BYRNE: In many ways, it is. It’s her worst enemy and her best friend, and it’s trying to harness the strength of that voice, but also trying to ignore the toxicity of it too. Like anyone’s inner voice, we have these dueling personalities, if you will, in some extremes more than others. It’s examining the human condition, which I’ve always loved about the show and been drawn to.

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Image via Apple TV+

Dierdre, what do you think Greta’s inner voice would be saying?

FRIEL: “Oh, God. Oh, God. Don’t mess up. Oh, God. Oh, god.” That would be a large part of Greta’s inner voice. She wants people to be happy and like her, and she’s nervous about herself a lot. Maybe that will start to shift, and it shifts a little bit this season.

It’s pretty clear that Greta values her friendship with Sheila more than Sheila values Greta. Why do you think Greta is so protective of Sheila, when that may not necessarily be the other way around? Do you think that Greta knows Sheila better than even Sheila realizes?

FRIEL: Maybe in some ways. Isn’t there that thing that sometimes people know things about you that you don’t know about yourself? My reaction to the characters was that I think Greta really looks up to Sheila. She sees her building something in a time when women were not doing that for themselves. She’s so beautiful and so fit and has this wonderful family, in Season 1, and I think that’s a big draw for Greta. It’s like, this is what a woman should be like and this is what a person’s life should be like. But then, especially with the building of the business and seeing a future for herself, as an independent person, I think Greta is totally blown away by that, as an aspiration.

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Image via Apple TV+

The fight that your characters have with each other in episode seven is interesting because it’s probably the most honest they’ve been with each other, the entire time they’ve known each other. Rose, what was that scene like for you to shoot? When you do a scene like that, that’s upsetting as characters, but fun as actors, what does that feel like, in the moment?

BYRNE: It was very windy, during the external. I have to mention that. And there were a lot of seagulls or birds.

FRIEL: By the time we were doing Rose, the light kept changing and all of these cars kept going by. There were a lot of challenges.

BYRNE: You’re dealing with noise, so you have to go again. And then, there are planes, on top of it. But I love that scene. When I read it, I was scared. I was like, “Oh, no. Oh, God.” It’s a terrific scene with great writing. I’ve not seen it yet, but it was a lot, on the day.

FRIEL: It was funny because it was one of the first times I’ve ever been able to be in a really intense scene, and then they’d cut and we’d laugh while they’d reset.

BYRNE: And then, we’d get cold. It was quite cold.

FRIEL: And Rose was in a leotard tank.

BYRNE: I hope it’s satisfying because it’s a raw conversation.

Rose, what was it like to be doing aerobics with Rory Scovel, and then be dancing with Murray Bartlett (who plays Sheila's rival, Vinnie Green)?

BYRNE: I love the scenes where I get to dance because you’re so less self-conscious. You can’t make decisions about your performance, which is very liberating. It’s so boring watching an actress or an actor try to decide what to do. You’re like, “Oh, my God, that’s so calculated.” And when you have to do something physical, you don’t have that time. Those scenes are so important, particularly the one with Rory’s character because he’s trying. He’s valiantly trying so hard to connect with his wife, and they really do have this beautiful moment, before everything falls apart again.

It’s so interesting to watch the two of them doing aerobics because it almost feels like therapy, and it also feels a little bit like their foreplay. You’re not really sure what to make of that moment between them. And then, when we see her dancing with Vinnie Green, there’s just something about Sheila that feels very free, in that moment.

BYRNE: There are more moments like that in this season than ever. You see her becoming more and more liberated in different ways because she’s being a bit more honest. She’s still not completely honest, but there is a candidness about her that’s beginning to show. The armor is coming off a little bit.

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Image via Apple TV+

Dierdre, what’s it like to get to have Ian Gomez play your husband and to explore that relationship dynamic with him?

FRIEL: I adore Ian Gomez. I’m so lucky that he’s my acting partner. He makes all of the scenes that we do together so much fun. He made it a very safe space to do these very sexy things. The head shave scene in Season 1 was the second day I met him. I was like, “I might have to stick my hand down your pants.” It was just really wild to not know somebody and have that conversation, but he makes everything so wonderful and easy and comfortable. He just makes it so light. I’m very lucky to work with him.

Rose, I don’t think it’s too much of a spoiler to say that Sheila has a very clear focus, by the end of the season. How do you feel about where she is left, at the end of this season, and how do you think that could play into a third season, if we get to see more?

BYRNE: I felt excited by the end, with the potential for this next phase of Sheila. But also, it was daunting to embrace that ruthless side of her, at the end. That felt daunting. It was challenging, that final scene with Paul Sparks. It was, again, very windy in San Pedro. We were battling the elements, with the wind. But Paul Sparks is a wonderful actor and very funny. We have fun, despite the damage of the relationship with those two characters. What I enjoy about watching the series is seeing these people evolve. The evolution of a character, on any show, is always like the chapters of a novel, if you will. I hope we get a chance to do more of that.

Physical is available to stream at Apple TV+.