Thread: How much is too much cardio?

Stats - 6'4", 223 lbs., ~20% bodyfat, 2500-2900 calories per day (maintenance is 3300 - 3800). I've cut back lately to just a bit of low-intensity steady state for 15-20 minutes after weights but I want to add more in without killing myself. I start shooting an indie flick on the 31st so I'd like to safely cut as much as I can before that.

A few months ago, my cardio days consisted of doing the Stairmaster for 33 minutes - 5 minute warmup followed by 25 minutes of 2-minutes high-intensity/1 minute low-intensity and then a 3 minute cool down.

After plugging in all the age & weight variables into the machine it would read between 750-900 calories burned in the 33 minutes depending on what levels I could maintain.

Then I'd rest for 5-10 minutes and do HIIT on the treadmill for another 30 minutes - 30 second sprint at 12mph and then 90 second jog/walk. That'd burn another 700 calories or so according to the machine. I was exhausted and a sweaty mess but felt great having burned 1400 - 1600 calories.

If I wanted to add extra cardio during the week, sometimes on my 3x/week weight days (Rippetoe's Starting Strength - kicks my butt, btw) I'd follow it up with 20-30 minutes of the Stairmaster as above.

Too much?

Swimming sprints the length of the pool and walking back for 30 minutes on non leg days. I have been doing this and it works well. In the past interval training by way of running or stairmaster would cause overtraining and kill my back, knees, and ankles after a few weeks. I have been doing this for several months with no pain and feel strong. Works for me!