I'd rather do the 120 and "fuel" as I think that it will help your performance to have something like Gatorade for performance/ hydration, maybe whether you have diabetes or not.
I don't intentionally run my BG up before I run. I won't let an accidental high get in the way of working out but I usually run up to 120 before I workout, if I'm planning a longer workout. If I'm doing a shorter session, I'll just cut it short and don't usually worry about it as shorter, anaerobic types of exercise seem to boost BG a bit.
I like to be around 120-130 before exercise and unlike AcidRock I prefer to allow my blood sugar to reach that level 3 hours post lunch without an extra snack. Of course, my exercise is only 45-60 minutes of walking rather than anything more demanding which probably makes a difference.
well...I like my BG to be 100 2 hours after lunch but, if the "tail" of the insulin is still lurking around, I'll snack on top of that before I run? ;-)
Does his gizmo show IOB? If it does, I test, check IOB and eat accordingly, really it depends on the numbers how I'm feeling. PE would be tough b/c you never know what the teacher's gonna dish out..."run laps" vs "talk about the birds and bees" will be two different plans!
Jay Cutler said he aims for 120-180 but I find that I don't feel that well run it runs high, although that may also be b/c I'm sort of high-strung about my BG? I think that your body needs some "fuel" (e.g. the 3 brands of gatorade, G1, G2, G3??) and I'd rather have some fast acting, "short" carbs "on board" instead of "eating" the tail of lunch although really, I think that some of both is good.
A lot of runners use that "Gu" and other brands of gels but I've noted most of them use maltodextrose that "deploys" slowly. If I have one 7 miles into a half-marathon when they are passing out "freebies", my bg spikes after the race (I run about 2 hours for that distance?).
I am not a scientist or doctor or anything like that but in my (2 years of running that my control has been generally pretty good, with adventures, of course!), I've found that I feel like I run best with more frequent, small doses of fast-acting carbs than "one big hump" and burn it off. I had one run where my pump failed last summer and another one where two sites sweated off (it was really hot, but not Austin hot...) and both times, when my BG got elevated, I felt like crap and had a really hard time running, a lot of cramps.