Don't just sit there looking at these photos of celebs working out — get inspired to move! Check out all the stars we saw headed in and out of gyms this week, and let them be your guide for carving a little fitness into your weekend.
Like actress Hilary Duff , we're also huge fans of pairing a sheer shirt over a sports bra — it's a great way to stay cool in the Summer.
Always consistent, actress Naomi Watts  was spotted leaving a fitness studio in Brentwood. She kept things sporty in an Adidas ensemble.
With hair like that, it looks like supermodel Rosie Huntington-Whiteley is ready for the runway! She was spotted leaving a Ballet Bodies class in Los Angeles earlier this week.