Well if you don't mind doing something different you could try panaerobics ie Heavyhands. It will build strength and endurance at the same time and depending on your approach also felxibility.
Sources. A book called heavyhands: the ultimate exercise - out of print but widely available used.
Look up the website.
http://www.heavyhandsfitness.com/content.aspx?idx=4
or for some comments on the excercise go to cbass.com.
Lots of people claim this does not work but I assure you it does unless you want to look like Arnold. For alaround toning and fitness it is one of the most efficient.
I use a medley fo between 10 and 20 excercies at about 1-2minutes per excercise depending on the weight used and if you go hard it can be brutal. its a short workout - no rests, and you have three variables you can control depending on your goals.
If yu do it in public be prepared for plenty of stares.
There is also a Yahoo group that supports this but it is not heavily used as heavyhands kinda died out inthe 80's ecause people didn't use them properly.
Cheers
J