This upper body workout with dumbbells is designed to help you build strength and definition in your chest, shoulders, biceps, and triceps. The workout consists of four sets of each exercise, with the reps decreasing from 15 to 10 as you progress through the sets. This gradual increase in weight and decrease in reps is a proven method for stimulating muscle growth and strength gains.

The workout begins with dumbbell bench presses, a great compound exercise for the chest, followed by dumbbell Arnold presses to target the shoulders. The workout then moves on to dumbbell alternate biceps curls to isolate the biceps, and finishes with dumbbell standing bent over two arm triceps extensions to work the triceps.

For best results, it's important to maintain proper form throughout each exercise. Always warm up before starting the workout, and stretch the targeted muscles at the end to aid recovery and prevent injury. Remember to adjust the weight of your dumbbells to ensure you can complete the prescribed number of reps with proper form. With commitment and consistency, this workout can help you achieve a stronger and more defined upper body.