Wally, the studies are being done as part of a larger body of research into at the University of Michigan
http://www.kines.umich.edu/faculty/full-time/horowitz.html
There are complete papers available on the site, the first one referenced is relevant but it is very technical.
This video shows how they go about it
http://videos.howstuffworks.com/university-of-michigan/768-exercise-and-insulin-video.htm
and this is a press release on the most recent research
http://www.eurekalert.org/pub_releases/2010-01/aps-wye012810.php
Less scientifically, last year I took part in the Big Blue Test organised by Tu Diabetes (an American forum).For World diabetes day, they got people on the forum to do 14 min of exercise. People did all sorts of exercise from yard sweeping, to running to skipping. They tested before and after. I ran on the treadmill and my bgl dropped from 6mmol to 4.3mmol.
I decided to compile some stats to see how people did overall.
120 people both type 1 and 2 posted findings with before and after readings I could interpret.
Of them
97 people’s blood glucose levels fell.
For these people the average fall was 25.5mg/dl (1.41mmol/l)
23 peoples blood glucose levels rose
For these the average rise was 11.6mg/dl (0,64mmo/l) Some of these people said that they continued and their levels fell later, others unfortunately said that their levels always rose after exercise.
I was quite surprised, even though I am convinced about the value of exercise I didn't think that it would have such an effect in so short a time.