The former Friends star gets up early in the morning every day to start her workouts, which include yoga, spinning and a trip to the gym.

"If I'm working, I'm up at 4.30, 5am. If not, between 8 and 9 am, because I'm a late-night person. But usually when I wake up, I'll make my standard cup of hot water with a slice of lemon in there," she told Well + Good.

"Then I'll go do a workout of some sort. I have a trainer, a wonderful woman who I do this spin-yoga class (with). We spin for half an hour, and then do yoga for 40 minutes. That's pretty intense.

"Then I go to a gym, where I do strength training or just my own thing on the treadmill, the bike, or the elliptical, just to change things up," she added.

The actress, 47, also admits she's a big fan of protein shakes, and revealed the recipe for one of her favorites.

"Usually I'll have a shake, with some sort of pure protein, then bananas, blueberries, frozen cherries, stevia (sweetener), a vegetable mix of dynamic greens that goes in there, maca powder, and a little cacao," she said.

"If I don't have a shake, I'll just have some toast and poached eggs with some avocado. Or millet cereal with almond milk and bananas - it's really yummy, and you can get it hot for winter months."

The Horrible Bosses star, who married Justin Theroux in a surprise ceremony last summer (15), recently confessed that her husband's sense of humour keeps her feeling young.

"I like making jokes. I'm lucky because Justin is the funniest person I've met and we make each other laugh. Laughter is one of the keys to staying youthful," she smiled.

And despite rumours about her changing appearance, Jennifer revealed that she's never felt, or looked better. "I feel better in my 40s," she confessed. "Not only do you feel better in your body physically but you're mentally better."