I've been using both since 2005 (DBs) and 2007 (KBs).
They are similar in some ways, but very different in others. Certain movements can be done with both, but the shape & versatility in the grip of a kettlebell makes it more suitable for some (and sometimes DBs are better for others).
For example - a heavy swing cannot be done properly with a dumbbell. This is a compound movement that uses the whole body. The clean & press is much easier with a kettlebell. You can also do deadlifts with a KB as opposed to requiring two for deadlifts. There are a million others. You can also do HIIT/"cardio" with KBs, not as much with DB's.
Both are great and IMO both should be used depending on what/when.
Start: 145lbs around December 2012(*Baby born November 2012)
Mini-goal 1: 140lbs*Achieved January 20th, 2013
Mini-goal 2: 135lbs*Achieved February 18th, 2013
Mini-goal 3: 130lbs*Achieved April 8, 2013
Mini-goal 4: 125lbs
Long-term goal: 120-125lbs
Losing while nursing... slow and steady
Maintainer 2004-2009 & 2 babies & now losing from Nov 2012 - present
Last edited by sacha : 05-10-2013 at 01:15 PM.