Why Choose Kettlebells Instead of Dumbells?

Don't choose! They are simply different strength tools and should be considered complimentary, not exclusive. The primary benefits of kettlebell training lie in the philosophy of the movements that have grown up around it. Kettlebell drills have historically focused on working many muscle groups in unison. Dumbbells have been more commonly used for isolation drills (preacher curl, front raise, etc.) in traditional western weight training. Kettlebells are also more convenient for explosive movement patterns which are frowned upon in most traditional mainstream gyms.

You can certainly perform many of the kettlebell drills with a dumbbell. Swings, for instance, just feel more pleasant and natural with a kettlebell. The round, compact shape and offset handle are made for this movement pattern. The wide, angular dumbbell shape makes the movement awkward and less intuitive.
Some kettlebell drills have dumbbell alternatives that offer lower difficulty levels. For instance, I love the added instability challenge that comes from perching atop two kettlebells in the Renegade Row... but, I often start my clients on this drill with dumbbells for a more stable base.
As I always say, "Use the right tool for the job." Here is a sample workout combining both kettlebells and dumbbells:

• A-1: Kettlebell swings - x20
• A-2: Dumbbell or kettlebell one arm suitcase deadlift - x6 (L,R)
• A-3: One leg, single arm deadlift using a dumbbell or kettlebell - x6 (L,R)
• Repeat 2-5x
  
• B-1: Kettlebell Turkish get up - x1 (L,R)
• B-2: Dumbbell or kettlebell one arm suitcase row - x6
• B-3: Kettlebell lunge cocktail (back lunge, straight up with a twist)
• Repeat 2-5x
  
• C-1: Alternating seated kettlebell or dumbbell press (from the floor) - x6
• C-2: Dumbbell renegade row - x6
• C-3: Kettlebell Figure 8 to hold
• Repeat 2-5x
  
• D-1: Kettlebell crush curl - x6
• D-2: Dumbbell tricep extension - x6
• D-3: Kettlebell snatch - x6-20 (L,R)
• Repeat 2-5x