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 30 min a day; the multiple-session group had three sessions of 10 min a day. Both groups exercised 3 days/week for 12 weeks. The control group did not perform any exercise. RESULTS: The single-session group showed decreases in weight (0.97 kg [95% C.I. = 0.09–1.83], p < .05), body mass index (0.43 kg/m(2) [95% C.I. = 0.03–0.81], p < .05), and fat mass (1.65 kg, [95% C.I. = 0.78–2.51], p < .01). Systolic blood pressure dropped in the single-session group (6.66 mmHg, [95% C.I. = 1.44–11.88], p < .05), and diastolic blood pressure dropped in the multiple-session group (3.38 mmHg, [95% C.I. = 1.44–5.88], p < .01). High-density lipoprotein cholesterol rose in the single-session group (4.08 mg/dL, [95% C.I. = −8.08–(−)0.07], p < .05) and dropped in the control group (10.75 mg/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 (16 mg/dL [95% C.I. = 5.64–26.35], p < .01) and the multiple-session group (12.16 mg/dL, [95% C.I. = 2.18–22.14], p < .05). Waist circumference decreased in the single-session group (2.65 cm [95% C.I. = 1.46–3.83], p < .001) and multiple-session group (2.04 cm, [95% C.I. = 1.51–2.73], p < .001). Low-density lipoprotein cholesterol levels rose in both the multiple-session group (−15.79 mg/dL [95% C.I. = −34.24–(−)3.78], p < .05) and the control group (−22.94 mg/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.