What's her secret? Reese is a regular on the roads around her LA home, favouring running as her main method of keeping trim. 'I like to run for about an hour and I'm big into working out with girlfriends,' she told In Style.
What's her secret? Rosie's a long time supporter of James Duigan's Clean And Lean diet, which means she sticks to fresh food and avoids refined sugar and caffeine. She starts her day with a smoothie made of fruit, almond butter, flax oil and coconut oil, and swears by Viyasa Yoga, which is a more vigorous take on your classic yoga.
Jessica Biel and Justin Timberlake
What's her secret? Pictured here running with former beau Justin Timberlake, Jessica Biel is an exercise devotee. In June 2011, she revealed her slimming secrets to That's Fit: 'For me, getting enough sleep, drinking lots of water, having a healthy diet and staying away from alcohol are musts. It's so boring, I know, but doing those things really helps.' As for exercise, 'Yoga is a constant for me because it keeps my muscles long and flexible. But now that summer's coming around, I'm planning on spending more time outdoors playing volleyball and jogging with my dog, Tina.'