Exercise and Omnipod

I used to suffer from high blood sugar after high intensity workouts such as circuit training and weight lifting.Since starting Omnipod, I have the complete opposite. For example, today I took a 1 hour sports conditioning class.This is mainly running/sprints and a few circuit exercises.I cut my pump delivery off 30 minutes before class.When I started my number was 130. My BG stayed around 130/136 for the first 45 min.Then it crashed to 75 and I drank juice (about 15 carbs).Anyone else experience this with exercise? How do you handle it??? I wish I could workout for 1.5 hours straight without any lows!