Highs after 1 hour+ Runs

I'm training for a half marathon at year's end and have been running since the first of the year. Most of my runs to date have been under an hour, but as I train for the half marathon I'm adding longer runs. This weekend's long run (6 miles in 1 hour 20 min.) was followed by 275+ blood sugar that wouldn't respond at all to insulin. After 3 hours of highs, I drank some Gatorade and quickly saw my blood sugar plummet.

I'm thinking dehydration. Any other folks have some advice for me. This has happened twice in the past couple of weeks and it just wrecks my days after a long run.

Might help to know how you administer insulin (pump/injection) - timing of insulin vs. exercise (and if on a pump what you do with basal rate during exercise) - whether level of exercise intensity has changed, and whether the amount of total weekly training has changed on average, what you're doing nutritionally before/during/after training (and whether that's changed) - and with the Gatorade whether you took insulin along with that...just some thoughts.

Do you see the BGs start to elevate before the run then if you've turned the pump down an hour before? Do you see your BGs rise normally (dawn phenom) in the morning - any chance the timing of your exercise ties in with that? Assume the under 80% would put you in Zone 3, so you'd be burning carbs. Like you said lots of variables. Did you check urine color to see about dehydration?

I'm out of heavy training mode at the moment, but during training I was shutting the pump down (temp basal of 0) during training sessions, taking a 1/2 bolus to cover carbs at the start of my workout (burning more than 15/hour), testing and taking in carbs (if needed) at each half hour interval after that - and using somewhat of a sliding scale (carbs/bolus) as the training sessions got longer. The other key was timing of insulin and nutrition both pre and post workout. Since the pump was off it took a while for the insulin to be active again when I turned it back on. Normally I used a reduced basal post workout, but fully covered whatever I had as recovery nutrition. Realize that still doesn't answer your question - but maybe a couple things more to consider - and perhaps something else to try when training. I'll mention that turning the pump totally off (as opposed to using a temp basal at 40% or something similar) was a total mindshift for me - but it worked incredibly well...as long as the timing of the other variables was in synch.

glad to help - keep me posted - good luck on your race