I do, I have a routine for muscle and cardiovascular endurance. Sprinting, suicides, up 'n downs (modified to include strikes), rollovers, and burpees. 5 sets of 10 of each except suicides, those I just do as many as I can in one go, which is usually about 30. Then I do my shadow boxing, and modified sit-ups (when I get to the up position I throw hooks). The whole thing is usually about 2 hours, and I think the only time I'm not pushing myself is the rest between rounds. And I stretch 3 times a day, morning, night, and after a light warm-up before I start my sprints.
My cardiovascular strength isn't bad, I'm 280 and run 3 miles every other day. (the above workout is 3 days a week. running is kind of my rest days.
The only thing I feel I really lack right now is power/speed... I should also really lose this weight, but it doesn't seem to want to go away. I trained 8 hours a week and dieted and I only lost like 5lbs in 3 months.