Julianne Moore has joked ''old age'' stops her from sticking to a workout routine.

The 52-year-old actress claims her aching muscles and joints prevent her from doing intense exercise, and while paddle boarding - a surface water sport which sees users paddle with their arms while lying or kneeling on a board - would be a great way to keep her figure trim, she prefers to take a leisurely approach to the sport instead.

In an interview with the November issue of Health magazine, she explained: ''I paddle board. But it's not the kind of exercise people say it is. I think you have to really paddle hard. But if you're just gliding along like I am, then no!

''The main problem is I can't do anything six days straight because I get hurt. That's the thing about old age - eventually your hip starts to hurt and you have to switch to do something else.''

The 'Carrie' star - who shows off her slender figure on the cover of the lifestyle publication - claims she sticks to a light workout regime to keep slim.

She said: ''I try to do Ashtanga yoga two to three times a week. I've also started working out with a trainer, doing light weights and a lot of jumping around.''

Julianne also relies on alternative medicine, specifically acupuncture, to alleviate any pain after a tough workout session, a method which she claims has also cured her of insomnia.

Speaking of the procedure - which involves penetration of the skin with needles to stimulate certain points on the body - she said: ''For back pain, it's amazing. I also had a period after my mother died where I couldn't sleep. I mean, I was just in shock for the longest time and didn't sleep for, like, a year. I was just a wreck. And I had some really intense acupuncture treatments, and it kind of reset my nervous system. So I think it's very helpful.''