Mary Elizabeth Mastrantonio: 'Acting frightens me, it challenges me ...'

Mary Elizabeth Mastrantonio - Robin Hood: Prince of Thieves, A View from the Bridge

Lots of actors in theatre roles do everything the same every night. I don't do that - it's too easy for your performance to go stale. Simple things such as turning to the left instead of to the right can make it fresh. I like to put the emphasis on different syllables during a run, because it provokes new reactions from the people you're working with, creating subtle changes in performances. You've got to play around - after all, it is called a play.

Creating a character also has a lot to do with the tone that other actors and the director create in rehearsals. If there's a lot of humour and openness in the setting, I find it becomes a more creative atmosphere.

I have to factor my family in to every career decision I make, the same as any other working mum. Change always comes with tears and loneliness, so you have to weigh up how bad it will be. If the sadness is temporary, you figure you can get over it. If it's long-term, you have to reconsider.

When the children were younger, it was easier to move around, but now they're settled in school I'm much less mobile. I did a year-long run about seven years ago in the Man of La Mancha, and that was very demanding.

I'm currently playing Beatrice in A View from the Bridge at the Duke of York theatre. I thought I could do it all: motherhood and the role, but I'm so tired. However I've never considered giving it up. Acting frightens me, it challenges me - you could say it ticks all my boxes. It's what I do. When I was younger, acting helped me to understand life. And if crying in front of 100 people, or whatever it is I'm doing that day, helps clarify things for other people - well, that's why I'm here.