Whenever Jennifer Connelly steps onto a red carpet in a strapless dress, we can't help but notice her toned arms. On top of great genes and hard work, she has celebrity trainer Nicole Winhoffer in part to thank.

The fitness expert, who has trained the actress for several years, recently visited InStyle offices to provide us a lesson in getting a few steps closer to Connelly's impressive arms. Her advice? Work out using an exercise that targets multiple muscles as well as the elasticity of your skin.

"What's really important about the arms is not just about the muscle tone but also about skin tone," Winhoffer said. "So we're working on elasticity and the way you do that is the quality of the movement rather than just focusing on the muscles we're working." Sounds great!

Watch the instructional video above for an easy-to-follow tutorial that targets those arms. The workout calls for 100 reps (yes, you read that correctly) that will truly make you feel the burn.