Effects of prolonged exercise versus multiple short exercise sessions on risk for metabolic syndrome and the atherogenic index in middle-aged obese women: A randomised controlled trial

Background: Many people, although they may recognise the positive effects of exercise, do not exercise regularly owing to lack of time. This study aimed to investigate the effects of prolonged single-session exercise and multiple short sessions of exercise on the risk of metabolic syndrome and the atherogenic index in middle-aged obese women. Methods: Thirty-six participants were divided into the single-session group, multiple-session group, and control group. The single-session group engaged in one session of treadmill exercise for 30min a day; the multiple-session group had three sessions of 10min a day. Both groups exercised 3days/week for 12weeks. The control group did not perform any exercise. Results: The single-session group showed decreases in weight (0.97kg [95% C.I. = 0.09-1.83], p<.05), body mass index (0.43kg/m² [95% C.I. = 0.03-0.81], p<.05), and fat mass (1.65kg, [95% C.I. = 0.78-2.51], p<.01). Systolic blood pressure dropped in the single-session group (6.66mmHg, [95% C.I. = 1.44-11.88], p<.05), and diastolic blood pressure dropped in the multiple-session group (3.38mmHg, [95% C.I. = 1.44-5.88], p<.01). High-density lipoprotein cholesterol rose in the single-session group (4.08mg/dL, [95% C.I. = -8.08-(-)0.07], p<.05) and dropped in the control group (10.75mg/dL [95% C.I. = 1.95-19.54], p<.01). According to post hoc analysis, high-density lipoprotein cholesterol increased more in the single-session group than the control group (95% C.I. = 0.61-21.88, p<.05). Glucose levels decreased in both the single-session group (16mg/dL [95% C.I. = 5.64-26.35], p<.01) and the multiple-session group (12.16mg/dL, [95% C.I. = 2.18-22.14], p<.05). Waist circumference decreased in the single-session group (2.65cm [95% C.I. = 1.46-3.83], p<.001) and multiple-session group (2.04cm, [95% C.I. = 1.51-2.73], p<.001). Low-density lipoprotein cholesterol levels rose in both the multiple-session group (-15.79mg/dL [95% C.I. = -34.24-(-)3.78], p<.05) and the control group (-22.94mg/dL [95% C.I. = -44.63-(-)1.24], p<.05). The atherogenic index increased in the control group (-1.06 [95% C.I. = -1.69-(-)0.41], p<.01). Conclusions: The findings indicate that prolonged exercise is superior to multiple short sessions for improving the risk of metabolic syndrome and the atherogenic index in middle-aged obese women. However, multiple short sessions can be recommended as an alternative to prolonged exercise when the goal is to decrease blood glucose or waist circumference.