Arms & shoulders: Squat and press
Stand with feet shoulder-width apart and a pair of 8- to 10-lb dumbbells between feet. Push hips back to lower into a squat (keep knees behind toes); grasp a dumbbell with each hand.
Engage core, push through feet, and rise to standing, bending elbows to bring weights near shoulders. Press weights overhead; lower weights back to shoulders, then back to floor. Repeat for 60 seconds.