Dumbbell lying pronation on floor

Lie flat on the floor with your face down and your arms extended straight out in front of you, holding a dumbbell in each hand. Rotate your palms so they are facing down towards the floor. Keeping your arms straight, lift the dumbbells off the floor by contracting your forearms. Continue lifting until your forearms are fully contracted and the dumbbells are at shoulder level. Hold for a moment, then slowly lower the dumbbells back down to the starting position. Repeat for the desired number of repetitions.