Karlie Kloss for Nike

It’s tank top and strappy dress season and that means one thing: lots of arm exposure. But you can stop killing yourself with the tricep dips and bench presses, because science has determined the number one move for strong, toned arms.

First lady Michelle Obama, center, flexes her arms for PBS Sesame Street's characters Elmo, left, and Rosita, right, during an event to help promote fresh fruit and vegetable consumption in the State Dining Room of the White House in Washington, Wednesday, Oct. 30, 2013. Sesame Workshop and the Produce Marketing Association (PMA) joined in Partnership for a Healthier America (PHA) in announcing a 2-year agreement to making healthy choices by using the Sesame Street characters to help deliver the messages about fresh fruits and vegetables. (AP Photo/Pablo Martinez Monsivais) ** Usable by LA and DC Only **
First lady Michelle Obama flexes her arms for Sesame Street’s Elmo at a White House event.

In a study commissioned by the American Council on Exercise, researchers at the University of Wisconsin-La Crosse compared eight of the top arm exercises and found the winning one that keeps both your arms and core engaged simultaneously: the triangle push-up. “The triangle pushup really targets all of the major elements of the triceps muscle—the long and lateral heads of the muscle,” explained Cedric X. Bryant, Ph.D. and Chief Science Officer at ACE, to youbeauty.com. “It elicited the most muscle activity.”To get the full effect of the workout, make sure to keep both thumbs and forefingers connected and your feet hip-width apart in a firm plank position.