We just bought a new treadmill today and i done some HIIT.It was great. i done 30 seconds fast walking then 30 seconds of real fast jogging (running). I done this for 20 mins then had a 5 min cooldown. I am 16 years old and my legs nor anything felt bad afterwards.i felt like a millionbucks. I was very sweaty and worn out but felt great.Should i do this about 2 weeks before I start to up it?I wanna do this 5 times a week then rest on the weekends.I lift weights on Monday,Wed,Fri and I want to do cardio inbetween them days and the days I lift I want to do cardio a hour or so after I lift.Does this sound good. i am looking to loose some fat maybe 20lbs.i wanna be able to see my muscles cuz im a bulky dude.