If given the choice, most men would use a barbell to do their exercises. However, if you want to maximize your calorie burning then you should be using dumbbells. Dumbbells challenge you in a 3 demensional space. They help you burn more calories by making you balance the weight. It also helps you even out muscle imbalances. Here’s what Men’s Health had to say about this subject matter.
Better for beginners. Having to stabilize the weight you’re holding in each hand improves coordination and activates more muscle fibers over all.
Help to even out strength imbalances between limbs (this is a problem especially common in beginners).
Safer than a barbell. If you can’t complete a rep, you can drop the weights. You won’t get pinned under them during a bench press or squat like you would a bar.
Allow you to go much heavier. Because of this, barbell exercises should always be done before dumbbell moves.
Better for working legs.You can do squats and deadlifts with dumbbells, but eventually the weight you use will get too heavy or cumbersome to hold. A barbell lets you use a big weight more comfortably.
Necessary for explosive exercises such as power cleans and snatches. You won’t be able to generate the same power with a dumbbell.
(CES, PES, CPT, BS)