Maya Erskine had never done strength training before being offered the role of a lethal international spy on “Mr. & Mrs. Smith.

” But for an actor whose gifts include a supreme corporeal awareness — like playing an awkward 13-year-old (when you’re in your 30s) on the acclaimed comedy “PEN15” — her prep starts with the body. “I approach things physically, externally,” Erskine said recently over Zoom from her home in Los Angeles. “When I try to do the internal first, I get very stuck, and it’s not in my body.

Physicalization helps me figure out who someone is.” But that journey from leaving Maya Erskine behind to embody Jane Smith wasn’t quite so simple. On the Maya end, the actor, who is married to Michael Angarano, had just had a baby — “My body was an absolute wreck, and I was shocked by how much everything changed” — while her endpoint was a young woman who had not only never given birth but had to be fit enough for running, jumping, punching, killing and the like.

“I was not a gym person, so I had to become that, and I fought against it a lot,” she admits. “The trainers and the nutritionist were like, ‘Maya, when we tell other people to eat a carrot, they’re like ‘OK.’ But with you, it’s, ‘Well, can I sauté it in brown butter?’ You make it so difficult.

’” We know the end of this uphill battle, however: challenge met, character nailed, praise garnered, Emmy nomination for lead actress in a drama series secured. For .