Hba1c better

Hello and welcome to the forum @locsel . It could be that both have played a role, although I minded to think the Trajenta may have had the greater impact, but it is difficult to say if you started both at the same time.
I am an exercise person. I use exercise to control my own blood sugars. Many T2 members on the site use low and very low carb diets which have brought their blood sugars down, some from very high levels. Diet too is a very affective way to bring down your blood sugars, but exercise has overall benefits to the body over time.

I am pro exercise. The amount of exercise will make a difference to your metabolism, especially vigorous exercise. When I say vigorous Im referring to your heart rate being over 120bpm and beyond for a sustained period of time. You are effectively burning off your blood glucose. Like a car the more you ask of the engine the more gas it will burn.

In the long run, excuse the pun, but in the long run exercise increases muscle mass, cardio and the vascular system. I would always advise people to start slow and build up to strenuous exercise. It's like building a house, if the foundations are solid your house is more likely to remain standing, much the same with exercise, build up slowly then there is far less chance of injury.