I just recently attended a seminar that a local company was putting on trying to sell HRM’s. Let me say this, they are very cool and extremely important to anyone student or adult who can get their hands on them. However, they are very expensive and the software it seemed required countless hours of training. It also included palm pilots and other pieces of technology based equipment. For our grade level (K-8) we decided to stick with the pedometers.
I personally use a strap less heart rate monitor and find that it is pretty accurate. I believe that grades 4 to 6 would have no problem using them. Of course the biggest concern would be cost, but if you have put in for a grant it looks like you have that part covered.
I am interested if you have heard back yet about your grant and which grant in particular you applied for