Normal HbA1c ("A1c") is between 4.6% and 5.4%.
If a person consistently has an A1c above 5.4%, then their average blood glucose is above 109 mg/dl (6.0 mmol/L).
The term "unfit" is too vague to be useful. To be more accurate, an A1c consistently above 5.4% increases the risk of receiving a diagnosis of prediabetes or diabetes.
An A1c consistently at 6.4% or above indicates cell damage is occurring and diseases typically associated with diabetes will develop.