Hi B
This is pretty much the same reccomendation as is made in the book "Heart Monitor Training for the Complete Idiot" by John L Parker.
Aslo Check out the articles at
this link which I cam accross while surfing the RW US forums a while back.
Another good source of information is
this web site.
It appears that a lot of people who start off running get hung up on speed at too early a stage, way before the body is ready which inevitably leeds to injury and to a lot of people getting disheartened and giving up. I am one who started off like this.
It takes time and patience to train your self to run at such a slow heart rate, when your heart rate goes above your target you have to walk till it goes back down and this feels like you are cheating. But if you perservere for about a month or two you soon should be able to keep running at the lower heart rate.
You also find that you start to run faster at lower heart rates. This can be seen by timing your run when you start training at your low heart rate and again when you can complete you run without walking while your heart rate stays low and periodically after that. You should find that you complete the same distance quicker and at a lower HR.
When I started running I use to run around 3.5 miles in 50 minutes with a heart rate in the mid 160's. Thats around 15 min/miles. I can now run my 13 mile long runs with a HR of around 136 at start drifting to around 142-145 at the end. I can run 7.8 miles at a HR of 155-160 in around 54:20 which is under 7 min/miles.
I attribute this to reading John Parkers book and following the princible he outlines. I took advantage of the dark nights to force my self to run at a slower HR. I also wore a normal tracksuit instead of my running tights etc so I did not feel too conscious when I had to walk to slow my HR down :)
I now run 4/5 times a week and my long run is 13 miles the rest are between 6.5 and 10 miles. With the exception of my one speed session I try and do all other runs at a HR of under 142. Even now it if I don't monitor it I will find my HR creeping up and my run will become a speed session :)
Just my 2 cents work