Denise Van Outen is looking radiant and sounding upbeat.

She may have gone through the heartbreak of separating from her husband Lee Mead, but she鈥檚 looking forward to the future 鈥 and the prospect of turning 40.

鈥淚 have lots of friends who feared their 40th birthdays but I鈥檓 not scared of it,鈥 insists Denise, who hits the milestone in May.

鈥淚鈥檓 going to embrace it and celebrate. I feel quite good about turning 40.

鈥淚 have a lot to be thankful for 鈥 I have a lovely daughter and fabulous friends and I am starring in my own one-woman play.

鈥淚t feels like a positive year for me.

鈥淚鈥檓 looking forward to having a party and having all my friends in one room.鈥

Denise and Lee met when she was a judge on Any Dream Will Do, the BBC1 talent contest which he won.

They married in the Seychelles in 2009 and had daughter Betsy in May 2010, but last July the pair confirmed they had split, though they remain amicable and are sharing childcare.

Of her approaching birthday, Denise insists: 鈥淚 look my age close-up, without my make-up on, believe me!

鈥淏ut I like to take care of myself and make an effort. Even when I had a newborn baby and had hardly slept, I still washed and blow dried my hair 鈥 it made me feel better.

鈥淎 good haircut can knock years off you, some people have the same style for ever but it is ageing.鈥

Turning 40 causes some people to reassess their life and make a list of things they still want to achieve, but that鈥檚 not Denise鈥檚 style.

鈥淚鈥檓 a do-er, I don鈥檛 wait until I turn 40 to do something, I just get on with it,鈥 she proclaims.

And that often means taking on gruelling challenges for charity.

Last year she walked the Great Wall of China for Leukaemia Research and she鈥檚 completed an Inca trek in Peru for Breast Cancer Care.

This year she鈥檚 planning to cycle in India and has promised to take part in Sport Relief.

She doesn鈥檛 know yet whether she鈥檒l be running, swimming or cycling but anything will be better than climbing Kilimanjaro with Cheryl Cole, Gary Barlow and others in 2009 for Comic Relief.

鈥淭hat was the hardest thing I鈥檝e ever done in my life,鈥 she winces.

鈥淚t was a hideous yet amazing experience. It鈥檚 the altitude that really gets to you.

鈥淚t was a very bonding experience. I became great friends with Kimberley Walsh.

鈥淚t鈥檚 very hard to say no to such a good cause. I鈥檒l be doing something for Sport Relief this year, though I don鈥檛 know what yet. I鈥檇 prefer to cycle as I like going out on my bike, but I鈥檓 not a very confident swimmer.

鈥淚 want Betsy to learn to swim though, so I鈥檒l be heading to the pool in the spring.鈥

But first Denise is tackling another challenge 鈥 taking her one-woman play, the first thing she has written, on a 海角视频 tour which includes Birmingham and Wolverhampton.

Some Girl I Used To Know sees her play Stephanie Canworth, a happily married, successful businesswoman. One night she is away on business when she is contacted via Facebook by her first love. All the old memories come flooding back, along with new temptations.

It鈥檚 set in a hotel room over the course of an evening, with Denise sitting on the bed in her hotel robe, using her laptop, for most of it.

She also sings a few 1980s songs.

鈥淚t鈥檚 not a jazz hands musical, it鈥檚 very realistic. The audience are in the room with you,鈥 explains Denise.

鈥淚鈥檓 excited about the play and proud it is actually being staged, from its beginnings two years ago with ideas scribbled on bits of paper.

鈥淚t鈥檚 the first thing I鈥檝e written. I鈥檝e had the story in my head for ages and told a few people, who said they liked it but I had to write it down.

鈥淚 had no idea how to go about that, so I asked my novelist friend Terry Ronald. We had lots of meetings in coffee shops.

鈥淭he hardest part was defining all the characters. I鈥檓 the only person in it so I have to create mental images for the audience of everyone else.

鈥淚 wanted to create it because I kept looking at female roles and couldn鈥檛 see anything that appealed to me.

鈥淚 tried it out for three days at the Curve in Leicester, which was really scary because I didn鈥檛 know what the reaction was going to be.

鈥淲hen I鈥檝e been on stage before it鈥檚 been in hits like Chicago and Legally Blonde, but this has never been done before. Thankfully, people seemed to like it.

鈥淚 have done a one-woman show, Andrew Lloyd Webber鈥檚 Tell Me On a Sunday. There鈥檚 nowhere to hide when you鈥檙e on your own, but I hope my experience with live TV and thinking on my feet will see me right.

鈥淚鈥檓 going to enjoy singing songs I love every night, songs that reminded me of growing up.

鈥淗old Me Now by the Thompson Twins always reminds me of spending the day by the seaside with this boy I went out with. He gave me a mixtape with that on afterwards and it always reminds me of feeling happy.

鈥淎lso Culture Club鈥檚 Do You Really Want To Hurt Me, as the lyrics are so poignant.

鈥淚 remember listening to Sonia鈥檚 You鈥檒l Never Stop Me Loving You in my bedroom and wishing it was slower because I like listening to the words. So we鈥檝e stripped it down and turned it into a ballad with strings.鈥

Denise was last in the Midlands a year ago for the Strictly Come Dancing live tour at the NIA.

鈥淚 have a couple of good friends who live in Birmingham so I鈥檓 really excited about spending time with them. They鈥檝e never seen me on stage before.

鈥淚鈥檓 looking forward to getting to know different cities. It鈥檚 like an adventure.鈥

Betsy will be joining Denise for part of the tour.

鈥淪he doesn鈥檛 really understand what I do. She鈥檚 far too young to see the play but she thinks everybody鈥檚 parents are like me and Lee.

鈥淥nce I asked her 鈥楧o you know what Mummy does?鈥 and she said 鈥榊ou talk to all the people鈥, which I suppose is kind of true!鈥

* Some Girl I Used To Know plays Birmingham鈥檚 New Alexandra Theatre from February 10-12 (for tickets ring 0844 871 3011) and Wolverhampton Grand Theatre on February 20-22 (ring 01902 419112).