28 must have been quite a shock. Was it a reading of fasting blood glucose, just a random reading or a deliberate attempt to measure blood glucose when it is at the top of a spike?
I recently got an HbA1c of 53 when expecting about 45. That was a shock too (and a severe disappointment).
I expect since you posted, you have worked out how Carb Manager was misleading you. If not, P1, below, is my understanding, i.e. only your food intake determines your macronutrient ratios and calorie count.
P1)
Your total food intake and its macronutrient proportions are determined by what you eat and drink. What exercise you take does not affect them directly. Of course, if you exercise a lot during the day and eat extra food afterward, your total calories go up and your macronutrient ratios will be determined by your resulting total food intake. To illustrate the point with an odd example: suppose you ate all your food from breakfast through your final evening meal/snack and only then took any exercise: no matter how strenuous the exercise, your macronutrient ratios would be exactly the same before and after the exercise. The same would apply if you took that exercise before breakfast or exercised during the day, and so on. At least, that's what I understand. (Of course, the exercise affects your calorie deficit).
P2)
Covid. Can you quote or refer me to any more evidence, observations and/or opinions about Covid and deteriorating T2 diabetes? I am grasping at straws for reasons my blood glucose control deteriorated so badly between June and November, this year. So far as I know, I did not have Covid.
TIA John