Need some ideas on how to get fit enough to play all court tennis. Have been doing cardio workouts on and off during the winter and no problems on the treadmill/elliptical type equipment, but trying to consistently hit hard ground strokes where you are generating a lot of power combined with constant movement all over the court leaves me winded quickly. Of course, the regular joe routine of desk work on weekdays and movies/dinners etc on weekends don't help either . Any ideas - increase duration of cardio? other exercises?