15 minutes is all you need to give your core the attention it deserves. This video is perfect if you've got only a little bit of time or you need a core addition after another class.
Krystina has slight modifications for everyone that will ensure that you're feeling the moves in your abs and not your hip flexors or back.
This class uses a yoga mat and a strap. If you don't have a yoga strap you can use a belt or a thera-band.