Glycemic control play an important role in the management of type 2 diabetes (T2D), with postprandial glucose proposed as a better predictor of diabetes-related complications than fasting blood glucose or HbA1c. Therefore, studying postprandial blood glucose fluctuations has high physiological and clinical sinificance.
Aerobic exercise is prescribed clinically to prevent and treat T2D because it improves glycemic control and insulin sensitivity in obese and hyperglycemic individuals. Aerobic exercise training is commonly accompanied by improvements in aerobic fitness and weight loss which independently influence glucose metabolism .
A single bout of aerobic exercise, that does not alter body composition or fitness of body, is sufficient to increase insulin sensitivity both in healthy , prediabetic and T2D persons. In healthy individuals, postprandial glucose tolerance has been shown to be unchanged, increased or decreased in the hours after a single bout of aerobic exercise.
In prediabetic and T2D persons postprandial glucose tolerance after a single bout of exercise has been found to be improved in some studies while unchanged in others but a reduction of oral glucose tolerance immediately following exercise has never been found. Thus it is found that the immediate effect of a single bout of exercise on postprandial plasma glucose levels differ between healthy and diabetic sub populations suggesting that it may be dependent on the subject’s underlying glycemic condition. Effect of single bout of exercise on plasma glucose kinetics following oral glucose ingestion would be influenced by the subject’s underlying level of oral glucose toleranc.
It is found that the postprandial blood glucose concentration following an oral glucose load was increased immediately following a single bout of aerobic exercise in subjects with NGT, this effect on glucose tolerance following exercise was not observed in persons with abnormal glycemic control (IGT and T2D). The immediate effect of a single bout of aerobic exercise on oral glucose tolerance differs between healthy and diabetic subgroups, implying an impact of the underlying level of glycemic control. The exercise-induced increase in postprandial glucose response found in normal healthy persons .
Several factors may explain the lack of increase in postprandial oral glucose level found in IGT and T2D persons .