Kelly Preston feels better than she has done ''for years'' since turning 50.
The actress - who has two kids, Ella, 12, and 23-month-old Benjamin with husband John Travolta - insists she is so happy she only feels 25 years old, but admits reaching half a century on October 13 did initially ''floor'' her.
She said: ''I feel incredible. It floored me for a bit, but now I love it and I feel better than I have in years. You are as old as you feel and I feel like I'm 25!''
Kelly - who lost three stone in the first 14 months after giving birth to Ben in November 2010 - credits her two children for helping her to feeling younger than her years and she insists losing weight through Kirstie Alley's Organic Liaison weight-loss program and two years of breast feeding has given her ''tons of energy''.
She added: ''I'm running after a two-year-old and keeping up completely.
''Ben runs around and three, four, five times a day we go outside and find frogs, millipedes and lizards. It's always, 'Mama, get it! Mama, get it!'
''I go up and down one or two pounds without worrying about it. I think I'd like to stay at this weight. I feel really healthy and I have tons of energy.
''The way I lost the weight was through Kirstie's [program], and breastfeeding, and the way I gained another pound is because of her! She sent me a box of unbelievably delicious sweets - Rice Krispie treats, homemade jams, coconut macaroons, you name it I plowed right though it!''
Kelly admits she had the ''best time ever'' during a short trip to Paris last month to celebrate her birthday, while she saw in the milestone earlier this month by taking in Barbra Streisand's ''magnificent'' Brooklyn concert with John and Ella.
She added to PEOPLE: ''I can't even put into words the experience because she was so magnificent. She said, 'Happy birthday,' to me [from the stage]. It was the best concert I've ever been to in my life, just magic. It was truly an amazing birthday.''