By Kim Peiffer
Jan 12, 2015 @ 2:45 pm

Allison Williams always looks flawless on the red carpet, and her appearance at the 2015 Golden Globe Awards was certainly no exception. She stunned in a strapless embellished Armani Privé gown, which showed off her super toned arms.

The bottom line? We're jealous. The good news? We've got the secrets to her flawless physique. The actress gets red carpet ready with regular Core Fusion barre workouts at Exhale (which sculpts her long, leans muscles into enviable shape through a series of ), so InStyle paid a visit to the New York City Flatiron studio, where Core Fusion teacher Julie Ann Earls showed us the moves to do to get toned arms like Williams.

All you need is a pair of 1- to 5-pound weights and you’re ready to try some moves that work all angles of your arms (and even your core). Watch the video above to learn how to do them at home. Bring on that strapless gown!