AIMS: To examine the oxygen (O(2)) kinetics during early recovery from peak exercise in patients with Type 2 diabetes and to examine whether oxygen O(2) recovery is associated with fasting glucose and HbA(1c) in this population. METHODS: Eighty-nine participants (52 men) aged 51.8 ± 7.1 years (mean ± SD) were divided into three groups: normal weight (BMI ≤ 25.0 kg/m(2)), overweight/obese without diabetes (BMI ≥ 26 kg/m(2)) and overweight/obese with Type 2 diabetes. Participants were assessed for their aerobic power (VO(2peak)) on a cycle ergometer, provided a fasting blood sample and underwent a series of anthropometric measurements. Early recovery period was measured for 60 s from cessation of exercise and expressed as percentage of VO(2peak) (higher percentage represents slower recovery). RESULTS: No significant differences were observed for age between the three study groups. Both the overweight/obese groups without diabetes and with Type 2 diabetes had higher BMI than the normal weight group, with no significant differences between overweight/obese participants without diabetes and those with diabetes. Participants with Type 2 diabetes had lower VO(2peak) than overweight/obese participants without diabetes and normal weight individuals (19.6 ± 4.8, 22.6 ± 5.4 and 25.7 ± 5.3 ml kg(-1) min(-1), respectively, P < 0.004 for overall trends). Participants with Type 2 diabetes also had slower recovery in oxygen O(2) kinetics after exercise, compared with both normal weight and overweight/obese individuals without diabetes (56.5 ± 7.7, 49.2 ± 7.2, 47.7 ± 7.4%, P < 0.004 for overall trends). Multiple regression analysis revealed that percentage of oxygen O(2) recovery was a stronger predictor than VO(2peak), BMI or age for fasting glucose and HbA(1c). CONCLUSIONS: Patients with Type 2 diabetes have lower VO(2peak) and prolonged oxygen O(2) recovery from peak exercise. However, only prolonged oxygen O(2) recovery was associated with fasting glucose and HbA(1c).