You've heard that squats are the king of exercises. But, it's hard to agree as to why this may be.
Well, let's take the arm positioning of this dumbbell squat as an example.
Placing some sort of mass in front of your shoulders result stressing your body in a way that it now must try to stop you from falling forwards. This leads to your 'core' muscles automatically working hard to 'stabilise' your body.
On top of this 'trunk stabilisation' as explained above, you're now having to squat up and down. This makes for a really good overall functional exercise that really strengthens all of your body.
So, if you've been practicing the easier squat movements, try this one.
Image Credit: ACE Fitness