High Intensity Interval Training - Heart Rate

[Heizenberg]

I've been trying to use HIIT principles in my workouts. This is my routine:
22 mins of treadmill excluding a 2 min warm up and 2 min cooldown (2 + 22 + 2)
I'm using my heart rate monitor to see that I don't climb to dangerous levels yet at the same time do HIIT type exercise. So my routine is 1-1/2 mins of 3mph walk at a incline grade of 4.0 alternated with 45 seconds of 6.1mph run at grade of 3.0. My heart rate is usually 125-149 for the easier interval to 155-179 for the 45 sec interval. I've been doing this for a month now. When I started out, the heart rate numbers were slightly higher for lower incline grades... meaning my heart and lungs are beginning to adapt. Now, my question is, IS THIS HIIT? Does HIIT's 'high' part have any relationship to heart rate? Obviously, I probably shouldnt be sprinting at a rate that makes my heart rate spike to 190+ (my reportedly dangerous levels since my age is between 30 and 31). So if this is NOT HIIT, how do I change this so that it is. My goal is mainly to drop body-fat levels and weight.

I'm not obese, but I'm definitely overweight (thin bones - 5'7" at 179lbs). I'm not fit, but I can handle the 22 min workout I mention above with minimal pain in the shin and feet, which I'm hoping will strengthen and adapt as i lose weight and build strength in them. My diet is not rich in fat, but not a super-low carb diet by any means. I'd estimate the breakup to be 10-15%fat, 40-50% carb/sugar and rest protein/legume/meat/egg types.

Any HIIT experts have any tips for me?

I am seeing some results (my pants are looser, belt has tightened one notch etc) but not close to the dramatic losses HIIT seems to advertise.

Thanks so much :). Any sound advice backed by facts welcome :)

[dug]

Dangerous heart rate level? Where did you read about that? I have not heard of that before and if there is such a thing I would like to know about it. I know that the max heart rate formual is very very general and I know some athletes heart rates get well into the 220 bpm range then 30 bpm resting. I seem to just tire when heart rate gets higher than I can maintain. For instance when time trialing on a bicycle I keep my heart rate around 180-185bpm. Highest I have ever seen on my HRM was like 193. I just seem to have no more and 193 seems to be my max. But I know max heart rate does vary person to person

Doug

[Heizenberg]

I do know that the formula HRmax = 220 - age_in_years is very general, but how do I guage what my personal HRmax is? I've taken it upto 190 before, but I got concerned when people I know mentioned that this may be damaging the heart instead of strengthening it.

I'm sure athletes have really low HRrest and can take a really high HRmax, so the question is how do I find out what my limits approximately are without getting all sorts of electro-cardio tests done in the clinic?

[CUE-BALD-1]

http://www.brianmac.demon.co.uk/hrm.htm

Try this link for some additional information. It has several embedded links too.