i am currently 210lbs at 6% bodyfat, i am 5'10'' by the way. I am able to maintain between 5-8% bodyfat year round. I accomplish this through a strict diet which allows one cheat day per week, along with 30-45 min of hard cardio per day, every day. I also use 250mgs of test and 200 deca, and 25-50 mg of proviron year round.
My cardio workouts are rotated between the stepmill(gauntlet) and the lifecycle stationary bike. For example, a typical 45min workout on the gauntlet will go like this: I use the manual program which allows me to vary the intensity instantly. I will do 5 min at the top setting(level13) followed by 1-2 min at level 9, then hit level 13 for 5min, etc. I will mainly do steady state cardio on the lifecycle which consists of level 18 or 20 for 45 minutes.
Keep in mind that these are very intense cardio workouts which probably 99.9% of the members on this board would be unable to complete. You will need to adjust the intensity to suit your individual fitness levels.
Trust me, the gauntlet(stepmill) is the machine that will give you the best cardio workout in the gym bar none. I am a former hockey player and this machine along with the stationary bike was at the core of my cardio training.