I'm hoping for a no, but I'm pretty sure this is bad, I just wish it weren't

Lately on my off-lifting days, thats 3 days a week, I have been doing 45 minute cardio. I try to get 2.5-3 miles in 30 minutes on the treadmill, then I hop on the bike and get 15 minutes, every 5 minutes doing high intensity

So for the treadmill, I don't go below 145 HR, and often go up to 181 just trying to get my mile in, I have been trying a mile in 10 minutes, though its usually taking me about 13 minutes. And then on the bike, I go to about 145-150 HR and then cycle for 30 seconds to get my heart rate shooting up to 180, and then I immediately slow down and let my heart get to around 145-150 again.

Now, am I doing too high intensity for such a long period of time? I have been getting really frustrated lately, wish my fat loss kind of stopped, and I just want to get to my goal of 8%BF, while I am currently 16%, with not much muscle.

No, you are fine. 3 days of intervals might be a little excessive. It might be better to do two interval sessions per week and one 45 session of moderate intensity steady-state. All workouts can be 45 minutes.

Sounds good. I also do 20 minute moderate intensity stairmaster 2 days a week before lifting, is that even effective, you think?

btw I have been fasting with those 45 minute sessions and an ATW shake or Lean Body breakfast shake on lifting/cardio days

Sounds good. I also do 20 minute moderate intensity stairmaster 2 days a week before lifting, is that even effective, you think?

btw I have been fasting with those 45 minute sessions and an ATW shake or Lean Body breakfast shake on lifting/cardio days

I'd do the cardio after lifting, personally. Otherwise, it sounds fine to me. You just may want to consider doing the 45 min session later in the day or at least having a protein/water shake first to help prevent catabolism.

If you keep the fasted 45 min sessions, that's fine. Just see how you progress and if you find yourself burning muscle, stop the fasted high intensity cardio. If you see yourself only losing fat, great. If you're losing neither, chances are your diet needs work.

Sounds good to me, dude. Others have made good suggestions, but generally, that's great.

Keep up the good work!

I'd do the cardio after lifting, personally. Otherwise, it sounds fine to me. You just may want to consider doing the 45 min session later in the day or at least having a protein/water shake first to help prevent catabolism.

If you keep the fasted 45 min sessions, that's fine. Just see how you progress and if you find yourself burning muscle, stop the fasted high intensity cardio. If you see yourself only losing fat, great. If you're losing neither, chances are your diet needs work.

I agree. I wouldn't do cardio before lifting. I'm really not a fan of high-intensity fasted cardio. But karatetricker is right. Evaluate if it works for you based on your progress. You don't want to be losing muscle. In terms of fat loss, I don't really think it's all that much better. Focus on diet too, absolutely.