As Jeannie said- you probably are seeing a glycogen (not glucagon- glucagon is the hormone that opposes insulin) to glucose conversion after you exercise- your muscles are unable to store much energy even if you don't have diabetes, and if you are insulin resistant- you store even less- so your body has to create the glucose you need for energy while you exercise.
I'd like to say something about the Januvia- it sounds like you take it like you would take an aspirin for a headache- it doesn't work that way. It takes from 2 weeks to 3 months to see the effects of Januvia. It has to build up in your body, and it works to keep you from spiking after eating carbs- it won't do anything for after exercise highs. If you only take it intermittently, it won't do you much if any good-
Also, if you want to eat yogurt- F A G E and OIKOS are greek style low carb/ high protein yogurts. Buy the plain in any fat level you want ( 0%, 2%, full fat), add a bit of your favorite flavored no sugar sweetner (I use vanilla flavored Stevia, lemon ,lime, koolaid)- I even mix in mocha flavored peanut butter at night sometimes.
good luck with your numbers
I just want to live happily ever after-every now and then. Jimmy Buffett