BG rises after Workout

I have always have a issue of high BG than what I had before the workout. I do 1 to 1.30Hr workout 4 times a week usually 2 hrs after my dinner. Before the workout I take a note of my readings on Dexcom. Every time, it turns out to be higher after workout, usually 30-40 points higher i-e If its 130 before then 160-180 after workout.

Note this always happens if I workout after dinner (2 hrs after dinner). Even I don't use temp insulin to reduce basal while I'm in gym. I do both cardio and weight training. Just water during workouts.

My routine:
Dinner: Starts between 6-7PM
Workout: Starts between 8-9Pm and last for 1 to 1.5 hrs.

Any suggestion/advice would be highly appreciated.

This is pretty normal for that length of workout, especially since your are doing strength training too. It is likely your BG drops quite a bit around 2-3 hours afterward, have you checked?
There are medical reasons why this happens, I'll let someone else chime in with the nitty gritty details.

That's where is the weird part starts. Even after 2-3 hours it doesn't drop that much. I usually take herbal/green tea before going to the bed. No snack whatsoever pre/post workout.
Also, since I adjust my basal recently, my BG is pretty much normal before the workout but stays little above after workout.

I take about a half unit from my pump before a workout, and that's solved the problem. Also, I've found that lifting heavy drops my blood sugar significantly.

From what I read in a book, the reason it goes up is that the exercise increases some other production in the liver, which in turn increases glucagon. That's WHY it goes up, but I find it really hard to figure out how to fix it.

I have the same problem, but I find that mine drops precipitously during exercise if it's straight cardio, but not if it's just weights. In either case I go up about 50-60 points, sometimes more, about two hours after. Since I also work out in the evening, I don't want to overcompensate and go low overnight. Not fun. I've managed to get the lows during exercise under control but I have yet to figure out how to control the spike after.

Leah, I won't take a chance as I know if my BG level dropped down during the exercise, then I will messes-up my whole workout.
I'm thinking about changing my dinner meal plan and see if this makes my BG uniform.

Wandering is onto it.

It sounds like a 2 fold item.
Part 1: If you're doing more lifting than cardio, you're probably going anaerobic, which will cause an increase in BG b/c you're not burning carbs anymore.
Part 2: Your liver is responding to the increase muscle activity by dumping some glyogen into blood stream, and when you stop working out, you're not giving your body a signal that you're done...so it continues to dump for a short time, thinking that "your body needs it".

If you are going to continue a similar routine w/ anaerobic activities like weights, you might try something similar to what Leah does (a small bolus to help combat, or perhaps an increased basal an hour beforehand). This will be unique to everyone though, and may vary based on how much actual aerobic vs. anaerobic activity you're doing at the gym.
Additionally, after a long aerobic activity (where the liver has been dumping glycogen to try and help), you might try drinking a glass of milk (good protein/carb mix) to try and help "flip the switch" that lets your body know it's not working out anymore since the blood will go from muscles to the stomach to help with metabolic breakdown of the food. You'll want to bolus for the milk of course. But again this is going to be a variable bolus based on the intensity/duration of the activity.
So it will take some trial/error/record-keeping to get it dialed in appropriately.

I have the same problem. I plan on testing the following workout:
1-1.5 Hours Weight-lifting
30-45 min Running

My hope is weight-lifting rises will be counteracted by running at the end of the workout

Try exercising before eating dinner. After dinner is always complicated because of insulin bolus and food digestion timing. If you do that a few times you may find that your BG is going up not because of the exercise per se, but because of your meal. I'm not saying you need to exercise at a different time, but trying it a few times can help you isolate some of the different variables that can affect your BG.

Have you seen this? Gary has a lot of good info/advice.

http://www.tudiabetes.org/video/live-interview-the-athletic-diabetic-with-gary-scheiner-cde

I'm having the same spike but it feels scary to bolus before a workout. For example,the other day,I was 103 and I ate a pretzel rod with PB before I went outside to practice soccer with my son for about 45 min. I did about 10 min of drills personally. When I came in I was 200. Im going to try the small bolus and see what happens.