Popsugar Health & Fitness Charlee Atkins Plan Bodyweight Upper Body and Core Workout From Charlee Atkins Want Stronger Arms and a Toned Core? This 20-Minute Circuit Can Help Get You There 24 February 2021 by Colleen Travers View On One Page Photo 3 of 6 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 3 Butterfly Sit-Ups Lie on your back, and open your legs into a diamond shape with the soles of your feet pressed together and your knees wide. Extend your arms overhead. Inhale and squeeze your core as you roll all the way up to a seated position, touching your hands to your toes. Exhale as you lower back to the starting position. Keep your core engaged and move with control, instead of flopping down on the mat. Continue this movement for 40 seconds. Previous Next Start Slideshow Charlee Atkins PlanTrainer Tips20-Minute WorkoutsArm WorkoutsBodyweight WorkoutsAb WorkoutsStrength TrainingWorkouts