I am a keen distance runner. Typically I run between 45 and 55 miles a week. My A1C is 5.8% and has been at about that level for 2 years. My BMI is 20.1 (i’m of slim build.). I am 46 years old and of Indian Ethnicity. I have always religiously avoided sugar/refined carbs and and I decided to give up alcohol in 2002.

My fasting blood glucose is only 5.2.

The problem I have is that reducing the amount of carbohydrate is my diet really harms my running performance – it really has a big impact. (I’ve really tried on this. I eat very quality carbohydrate – porridge oats – though I am addicted to bananas.)

I have two questions.

Is fasting blood glucose or HbA1C a better measure of disease status?

Is it worth sacrificing my sports performance to reduce my HbA1C?

I see you are posting in Welcome to the BSD so you are probably not on the 800 Fast but still looking to reduce your BG. You obviously dont need to lose weight so there is no reason to be quite as strict with the carbs as those who are trying to do both, lose weight and lower BG. Maybe you should try the Med Diet which allows more carbs as does the 5;2 plan. Although not athletes many of us adjust our exercise to suit this diet rather than the other way round.

I dont understand the first question, surely BG and HbA1c are the only ways of knowing how your condition is. Or do you feel that if you are fit and exercising you are controlling your condition anyway. Keeping fit is great. As for sacrificing your sports performance for better BG, then for me there is no question about it, I want to be drug free and diabetes free much more than I want to be slim. Ideally I would like both and having one does not rule out the other. You are just going to have to find a balance.