[Sponsored by GNC] Join fitness trainer Katie Austin for a no-equipment, 20-minute total-body routine that focuses on lengthening and toning your muscles. During this feel-good workout, you'll work on oblique knee pulls, plié squats, lunges, Russian twists, and other muscle-burning exercises that will make you feel accomplished. To get started, just find a space where you can move your whole body! And, if you'd like some cushion for your knees, grab a mat.

Get Summer Ready with GNC [1].

Find more than 100 on-demand workouts from Austin on the Katie Austin app [2].

Follow Austin on Instagram [3] and YouTube [4].

Austin's Outfit: LSKD